The contact stress and bending stress are calculated and comparatively analyzed with the same meshing tooth width by using three methods of the national standard formula based,Romax software（full tooth meshing） and Romax software（staggering tooth meshing）,and thus the effects of different meshing tooth width（that is different staggering tooth amount） on the gear bending stress values are researched.While by using Locati rapid fatigue testing methods,the operating gear bending fatigue tests are carried out and the bending stress of each load with three methods are determined,the bending fatigue limit estimated values are obtained.By comparing the bending fatigue limit estimated value,the bending stress credibility of staggering tooth meshing is determined based on Romax software（staggering tooth meshing）,the reference method for the gear bending stresses calculated with staggering tooth meshing is provided.