The geometric model of the scroll gear of the three vortex scroll compressor was established by using the profile equation,the variation law of the working chamber volume with the spindle angle was obtained by using the integral method,and the working process of the three scroll compressor was analyzed.The results show that the six working chambers complete the suction,compression and exhaust process with π/3 cycle respectively.The calculation method of volume chamber pressure in the compression process of the three scroll compressor was given,on this basis,the volume characteristics of the working chambers,the variation law of the pressure in the working chambers and the variation law of the exhaust hole area of the single scroll compressor,double scroll compressor and three scroll compressor were compared and analyzed.It is concluded that the exhaust of the three scroll compressor is more stable and it is more suitable for low pressure ratio occasions.