Aiming at the problems of solid thread gauges including difficult to process, high cost, easy wear and cumbersome verification procedures, a digital measurement model establishment and parameter calculation method of thread gauge based on three-dimensional point cloud was proposed. In order to realize the digitization of the physical thread gauge. First, the 3D digital model was obtained, and the key parameters of the model such as large diameter, middle diameter, small diameter, pitch and tooth profile angle were obtained. Secondly, the single error and comprehensive error of the model are analyzed, and the relative error of each parameter is less than 5%. Finally, the uncertainty and extended uncertainty of each parameter of the digital model are calculated, which proves the accuracy of the digital measurement model of thread gauge. The results provide a research basis for the digital development of thread gauge and have reference value for the digital transformation of measurement industry.