Automotive drive axle housing is one of the main bearing components. The structure and the design parameters of Rear drive axle housing, which play a decisive role on the reliability and durability, have also directly affected the performance of automotive, such as driving force of economic performance, the ability of the economy, running smoothness, passability mobility and maneuverability. This paper introduces carcasses and the design, calculation and the main parameters of strength checking parts of the 2.25 tons light truck rear drive axle housing and axle shaft. At first this paper introduces the topic of meaning ,purpose and background of the main issues to be resolved, the overall design of the content outlined followed by detailed。 Bridge drive the type of shell is divided into a whole-casting, stamping welded steel plate and combined. According to the design requirements, I choose the welded steel plate stamping and Analysis, design, and conduct further strength checking. On the type of axle, such as semi-floating, 3 / 4 full-floating and floating, According to the design requirements it should be the form of semi-floating axle and then do the same thing. Analysis, design and strength check calculation. At last, a spline axle strength-calculation can determine other axle parameters and materials and heat treatment.