Based on the physical model of capillary pumped loop (CPL) system, the phenomena of pressure oscillation are simplilied and analyzed. From a set of non-linear differential equations, the influence ofsystem parameters on the performance of the CPL is discussed, including the working temperature(the Set point), loop resistance, vapor volume etc. From the analysis, some measures were taken tohoprove the performance of the loop. Meanwhile, the reason why the deprive of the CPL occurs duringthe operation is given by analyzing the theoretical calculation results. Based on the physical model of capillary pumped loop (CPL) system, the phenomena of pressure-decreasing differential equations, the influence of system parameters on the performance of the CPL is discussed, including the working temperature (the Set point), loop resistance, vapor volume etc. From the analysis. some measures were taken from judging the theoretical calculation results .