The operating principle and structure of twoway proportional cartridge valve of LIQZO type of ATOS were analyzed mainly. Its simulation model by using AMESim HCD library was built. By referring to characteristic curve that manufacturer provided, the parameter setting of its simulation model was explored in detail so as to ensure the dynamic and static characteristics. Contrastive analysis of simulation curve and the sample curve shows that the built simulation model and the set simulation parameters are rational and feasible. The research achievement has reference significance for modeling of other proportional cartridge valve.