There are many structural forms of semi-axle, and here we mainly study three forms, namely, full floating semi-axle, semi-floating semi-axle and 3/4 floating semi-axle, all of which have their own advantages. According to this project, this design mainly adopts full floating semi-axle.Semi-floating semi-axle is mainly used in all kinds of cars and light trucks. Its main advantages are simple structure and low cost, but there are also some shortcomings, that is, the load it bears is complex;3/4 floating axle shaft has not been applied yet, because its lateral force bearing tends to skew, which will reduce the service life of the bearing to a certain extent;Full-floating semi-axle, which is supported in this form, has complex outer end structure, large hub size, heavy weight, complex structure and shape, and high manufacturing cost. However, the semi-axle works reliably and is easy to disassemble and assemble. It can be taken out of the semi-axle sleeve only by unscrewing the screws on the flange of the semi-axle, while the wheels and axle housing can still support automobiles and are widely used in middle and freight cars. Therefore, this semi-axle is adopted in this design.