Objective: To investigate the accuracy and clinical application value of using bright-field microscopy without any staining for identification of parathyroid glands during thyroid cancer surgery. Methods: Among a total of 357 patients undergoing surgical treatment for thyroid cancer during January 2016 to June 2017, 196 suspected inferior parathyroid tissues were found in 115 cases. A sample about 2 mm3 in size was taken from each suspected tissue, and then evenly divided into two parts. One part was crushed on a glass slide by compression method for parathyroid gland identification using bright-field microscopy without staining, and the other one was sent for intraoperative frozen pathological examination. The results of the two methods were compared using the results of frozen pathological examination as gold standard. Results: In 196 suspected inferior parathyroid tissues, 142 were identified as parathyroid tissue, 29 as adipose tissue, 17 as lymph node tissue and 8 as thymus tissue by bright-field microscopy without staining; 146 were diagnosed as parathyroid tissue, 27 as adipose tissue, 16 as lymph node tissue and 7 as thymus tissue by intraoperative frozen pathological examination. The sensitivity and specificity of the bright-field microscopy without staining for detecting parathyroid tissue, adipose tissue, lymph node tissue and thymus tissue were 97.26% and 100.00%, 93.00% and 97.63%, 88.00% and 98.33%, and 83.00% and 98.42%, respectively. The results of consistency test showed that there was a high consistency between the two methods, as shown by the κ value for parathyroid tissue of 0.948, adipose tissue of 0.875, lymph node tissue of 0.835 and thymus tissue of 0.835 and 0.704, respectively. Conclusion: The sensitivity and specificity of bright-field microscopy without staining for parathyroid identification during thyroid cancer surgery are high. It can accurately distinguish parathyroid tissue and other tissues, and thereby reduce inadvertent parathyroidectomy and wrong autologous transplantation. Meanwhile, it has the advantages of simple operation, less time-consuming and low cost. So, it is recommended to be used.