Abstract: Aiming at the problems that helium mass spectrometry leak detector cannot realize in-situ homogeneous mass leak detection and the low leak detection efficiency after helium background is contaminated, a leak detector with multiple leak detection gases is designed, and the selection of suitable leak detection gases according to the different needs can improve the reliability and efficiency of the detection results. In this paper, the quadrupole mass spectrometer has the characteristic of analysing many kinds of gas components, and with reference to the working principle of helium mass spectrometry leak detector, a quadrupole mass spectrometer as the core sensor leak detector is designed. In the structural design, the parts and controllers are designed in a split structure, and the whole machine is flexible to be split into combinations and can be used to set up four kinds of detection systems by itself. The gas inlet interface adopts a three-stage sorting structure, which can meet the demand of sample inlet under the pressure of 100 kPa~10⁻⁷ Pa and can realize the leakage detection of negative pressure and positive pressure. A linear calibration algorithm of the leakage detection signal is studied in the software, and at the same time, the partial pressure signal of the original software is converted into the leakage rate signal, which improves the reliability and efficiency of the leakage detection data processing. The performance test results and applications of the leak detector for multiple types of leaks indicating gases show that the performance of the leak detector is in good condition, and the negative pressure leak detection sensitivity is up to the order of 10⁻¹³ Pa·m³/s, and the positive pressure leak detection sensitivity is up to the order of 10⁻⁸ Pa·m³/s. He, Kr, CF₄, Ne, Ar, etc. were used as leak indication gases, and the leak detection sensitivity can be in the order of He>Kr>CF₄>Ne≈Ar. The results can provide technical support for the development of similar quadrupole mass spectrometry leak detectors and provide a basis for the selection of leak detection gases.