Gear bending fatigue test is an important means to evaluate gear bending fatigue performance. In this work, the effects of test process errors on test results were investigated to ensure the accuracy of test results. According to the method B in the national standard GB/T 14230-1993, the bending fatigue test scheme was made with symmetrical loading across five teeth. The finite element simulation and strain gauging were carried out to verify the correctness of the test scheme. The bending fatigue test of 18CrNiMo7-6 shot peened gear was performed by D-M method. The effects of gear geometric accuracy, clamping error and equipment loading accuracy on the bending fatigue test results were analyzed. The results show that the maximum error between the calculation of bending stress of tooth root and the results of finite element simulation and strain gauge stress analysis was 8.7%, which meets the engineering requirements. Under 99% reliability, the bending fatigue limit of 18CrNiMo7-6 shot peened gear was 642 MPa, which is 28% higher than 500 MPa of MQ grade in the GB standard, suggesting that the standard design is conservative. The geometric accuracy of the gear and the accuracy of the test equipment have great effects on the bending fatigue test results. Considering the comprehensive effects of the errors, the effect on the test results is 2.43%.