As the substitution of the traditional heat pump system, the heat pump driven liquid dehumidification hybrid system and the temperature-humidity independent control system have great application potentials. In this paper, the ideal reversible processes of the three types of systems are built theoretically with their mathematical models, in order to compare their maximum coefficients of performance COPs. The results show that the COP1 of the ideal heat pump driven liquid dehumidification hybrid system is the maximum and the COP2 of the temperature-humidity independent control system is the minimum with the COP3 of the heat pump system falling between both. The COP1 increases by 100% with an increase in the indoor design temperature and relative humidity while the COP1 decreases with the increase in the ambient temperature and relative humidity. The COP2 of the temperature-humidity independent control system can be affected more significantly by supply air temperature difference and angle scale. In an ideal heat pump system, low-grade heat source utilized to reheat the processed air is a superior choice. The study results in this paper have guiding significance for the selection of three types of systems in practical applications.