Based on the reciprocating compressor,the dynamic response laws of the small end bushing abrasion on the basis of the dynamics simulation model were analyzed. According to the method of non-linear contact collision modeling,the dynamic model of small end bushing-crosshead pin joint was established. By changing the clearance between small end bushing and crosshead pin,the contact-impact parameters under different wear states were simulated and calculated,and features of the contact impact force between small head bushing and crosshead pin were analyzed,also between crosshead and middle body. The response which provides guidance for extracting sensitive characteristics under the wear fault was obtained. The correctness of the simulation results are verified through experiments,which provide an advanced warning and diagnosis method for the wear failure of small end bushing.