In order to resolve the problems such as large fluctuation in high-pressure pump liquid level, frosting of pressure transducer tubing at the top of pump well and significant measurement inaccuracy of the liquid level gauge, this paper analyzes the physical properties of LNG in the pump well of the high-pressure pump in a LNG receiving terminal, and the working principles and installation method of the differential pressure level gauge. The research results show that: 1)the big change in LNG physical properties is one of the reasons for the large fluctuation of high-pressure pump liquid level; 2)the upper pressure detection point of differential pressure level gauge is located higher than the transmitter’s negative pressure side, which is the main reason for pressure tubing frosting at the top of pump well; 3)the liquid column formed at the bottom of the pressure tubing at the positive pressure side is the main reason for the inaccurate liquid level measurement of the high-pressure pump. In view of the three problems and their main causes, the following concrete measures are proposed: 1)add a heat tracing element at the positive pressure side; 2)change the installation method of the liquid level gauge; 3)closely control the operation parameters of the recondenser. The research results can solve the above operation problems of high pressure pump, and provides a new solution to the routine operation and maintenance of high-pressure pump in LNG receiving terminal.