Abstract: the positive pressure leak is to provide the reference gas flow in leak detection， leak detection system for pressure calibration or determine the leak size reference standard. With the wide application of helium leak detector suction gun， put forward higher requirements on the quantitative positive pressure leak detection method， the accurate calibration of positive pressure standard leak rate is increasingly urgent. This paper is the establishment of pressure leak calibration device by using constant volume method and quantitative gas method， through in-depth study on the performance of the device， to provide the theoretical and technical basis for accurate delivery and report for value.