An electromagnetic reversing valve mounting method, comprising: manufacturing a main valve body part (10), a first connecting pipe, and a second connecting pipe, welding the first connecting pipe and the second connecting pipe with the main valve body part (10), placing a piston connecting rod assembly (70) together with piston members (72, 73) into the main valve body part (10), and manufacturing a first sleeve part (40) and a second sleeve part (50), the first sleeve part (40) being in sliding fit with a first piston member (72) of the piston connecting rod assembly (70), the second sleeve part (50) being in sliding fit with a second piston member (73) of the piston connecting rod assembly (70), the first sleeve part (40) being fixedly connected to the main valve body part (10) by means of a first connecting seat (20), and the second sleeve part (50) being fixedly connected to the main valve body part (10) by means of a second connecting seat (30), so that the first piston member (72) and the second piston member (73) can be smoothly loaded into the first sleeve part (40) and the second sleeve part (50), so as to reduce the problem that a piston bowl of a piston member may be damaged when a valve body part is mounted.