In order to improve the rate accuracy and rate stability of the laser gyro test turntable, a fixed angle time measuring device is developed in this paper. The device uses the high-precision clock as the reference to uniformly encode the axis angle data of the turntable, and generates degree pulse and cycle pulse signals. The clock pulse is counted with the degree pulse as the fixed angle interval, and the time code of the fixed angle interval is read by the computer. The computer calculates the rate accuracy and rate stability according to the requirements of the national standard. This technology can effectively eliminate the errors caused by the rate accuracy and rate stability of the laser gyro test turntable, and improve the rate accuracy and rate stability of the laser gyro test turntable. After using this technology, the rate accuracy and rate stability error of the laser gyro test turntable are reduced to one tenth of the original.