Background and Aims The incidence of thyroid cancer is growing rapidly. Long-term endocrine suppression therapy after surgery for papillary thyroid carcinoma (PTC) is an important measure to reduce disease recurrence. However, multiple outpatient clinic visits of patients significantly increase the medical burden and costs, and different physicians may have different standards for drug dose adjustment. Therefore, an assistant medication dispensing system is needed to facilitate accurate dose adjustment in clinical settings. In this study, the authors independently developed and designed a specialized intelligent dose adjustment assistant system for postoperative endocrine suppression therapy, so as to facilitate and simplify the dose adjustment process in clinical practice.Methods According to the principle and related guidelines of thyroid stimulating hormone (TSH) suppression therapy, the medication adjustment goals and detailed rules of TSH suppression therapy were established, and were coded into computer language to build a dose adjustment software system combined with network server, and clients' and users' terminals. The patients who received TSH suppression therapy after surgery for PTC at the outpatient clinic from February 2021 to January 2022 were enrolled, and were categorized according to the postoperative time as initial treatment stage (<1 year) and follow-up stage (≥1 year). The general data were collected when the patients entered the study, which included gender, age, body mass index (BMI), scope of surgery and recurrence risk stratification, and the parameters were recorded during dose adjustment, which included the time of postoperative reexamination, the indexes of thyroid function, the number of cases with hyperthyroidism or hypothyroidism related symptoms, and the number of cases with good control (the TSH value was within the target range). The program of the intelligent dose adjustment assistant system included two computer-aided adjustments following the record of the results of the physician's adjustment. First of all, according to the parameters recorded when the patients entered the study, a new medication plan was automatically generated by the system, and the patients received levothyroxine treatment according to the new scheme until the second reexamination. In the second reexamination, the new parameters produced after dose adjustment were recorded, and a new medication scheme was generated again by the system, the patients were continuously treated with levothyroxine according to the second new scheme until the third reexamination, and the new parameters produced after medication adjustment were recorded at the end of the follow-up. The control rates of TSH level and other relevant clinical variables between the results of two system adjustments and the results of physician's adjustment before system adjustment were compared and analyzed.Results A total of 99 patients in initial treatment stage were included, 2 cases (2.0%) were lost to follow-up, and 97 cases completed dose adjustment follow-up. The control rates of TSH level of the two system adjustments were higher than that of the physician's adjustment (57.7% vs. 34.0%, P=0.001; 63.9% vs. 34.0%, P <0.001). There was no significant difference in the incidence of symptoms related to hyperthyroidism or hypothyroidism (P=0.791, P=0.267). A total of 50 patients in follow-up stage were included, and all of them completed dose adjustment follow-up. There was no significant difference in the control rate of TSH level between the first system adjustment and physician's adjustment (50.0% vs. 36.0%, P=0.143), but the control rate of TSH level of the second system adjustment was higher than that of physician's adjustment (66.0% vs. 36.0%, P=0.007). There was no significant difference in the incidence of symptoms related to hyperthyroidism or hypothyroidism (P=0.180, P=0.180). The results of subgroup analysis stratified by sex, BMI, scope of surgery and recurrence risk were generally consistent with the results of overall analysis. There were no statistical differences in control rates of TSH by physician's adjustment and two system adjustments between patients in initial treatment stage and follow-up stage (all P>0.05).Conclusion In the process of endocrine suppression therapy after surgery for PTC, compared with physician's adjustment, the intelligent dose adjustment assistant system has considerable safety and higher control rates of TSH level, and can better assist clinicians to accurately adjust levothyroxine dose in PTC patients after surgery. However, large sample-sized, multicenter and prospective studies are still needed to further verify the above conclusion.