Based on the establishment of system mathematic models for civil aircraft cabin pressurization system, simulate and analyze system performance under flight envelope, as well as its performance under abnormal conditions, such as single failure of air conditioning pack, emergency depressurization and burst depressurization. The result shows that single failure of air conditioning pack has little influence on system performance, and emergency depressurization can meet the requirement of airworthiness standards. For burst depressurization, cabin depressurizes fastly using near the same pressure dump time with different leak area.