The analysis and comparison of contact stress of quasi-transverse double-circular-arc gear and transverse double-circular-arc gear as well as noamal plane double-circular-arc gear are carried out.And the analysis of contact stress for quasi-transverse double-circular-arc gear is finished when different gear helix β is selected with different setted helix angle β0.The analysis shows that quasi-transverse double-circular-arc gear has a greater advantage in processing technology and contact strength.