This paper introduces a new-type resonant water-level sensor performance test system. The ultimate aim of this system is to obtain the characteristic curve of tested sensor, and engineer can use the curve to judge whether the performance of the tested sensor has reached the pre-established standard. This system takes the ADμC812 as main controller, and its hardware circuit consists of pressure value of water-level measurement circuit, frequency measurement circuit, switching circuit of gas chamber. The central idea of this system is that it adopts a new-type frequency measurement method and numerical processing method to obtain the characteristic curve of tested sensor, which eliminate the shortcomings of low precision, high error characteristics of traditional sensor tested system ,and greatly improved the system’s accuracy and reliability.