A study was carried out to investigate the effect of pump-assisted separate heat pipe (PASHP) on energy consumption and dehumidifying enhancement in the air conditioning system. In the experiment, four sets of PASHP filled into R134a as the working fluid were constructed. when the number of PASHP employed in the system changes from 0 to 4 sets at the constant inlet air state of 28.5 °C and 60% relative humidity, the apparatus dew point falls from 11.7 °C to 8.2 °C, the supply air temperature rises from 11.7 °C to 24.1 °C, while dehumidifying capacity of the system has ultimately increased by 29.5%. The index β (ratio between the cooling energy saved by PASHP and the total cooling capacity of the air cooling system with PASHP) is 40.4%, and the index δ (ratio between the cooling energy saved by PASHP and the cooling capacity of the air conditioner's evaporator) is 66.0%. The study indicates that the air conditioning system employed with PASHP can significantly reduce its energy consumption and improve its dehumidifying capacity.