Abstract: In this paper，the high sealing performance of heat pipe in spacecraft thermal control system is required，and a lot of study on leak detection of the heat pipe whose working medium is special heat transfer medium are carried out.For solving this question，the existing leak detection methods are analyzed.The leak detection of heat pipe based on chromatographic analysis technique is introduced.This paper introduces the working principle of leak detection of heat pipe using chromatographic technique，the design of the leak detection experiment system，experimental method data processing method.The heat pipe whose working medium is gas-liquid two phase flow of C₂H₆ is leak tested，its leakage rate is in the order of 10-8 Pa·m³/s，that provides a reference for the future of the heat pipe leaking detection.