In order to research the liquid leakage detection function of chemiluminescence immunoassay analyzer,the mathematical analysis model of the pressure detection system was established, and the influencing factors of the system pressure change were deduced. The influence of parameters such as pipe diameter, pipe length and pumping speed on the accuracy of pressure detection system was studied, the influence rule of system structure parameters and performance parameters on the pressure detection accuracy was revealed. The results show that the pipe length, pipe diameter and pumping speed of the sampling system have significant influence on the stability of the pressure detection system; a reasonable choice of the pipe length, pipe diameter and pumping speed is helpful to improve the stability and the accuracy of the pressure detection system.