In order to prevent hydrate from forming in gas pipeline during shutdown, it is necessary to calculate its safe shutdown time. During wet natural gas pipeline shutdown, heat exchange will occur between media in gas pipeline and their surrounding environment, and hydrate will form in pipeline if shutdown time is too long, which will result in difficulty during restart. Applied is the multiphase flow simulation software to study safe shutdown time calculation methods, used is the finite element method to analyze temperature variation of buried pipeline and its surrounding soil during shutdown, compared is gas temperature with hydrate formation temperature, calculated is wet natural gas pipeline safe shutdown time and studied is the safe shutdown change rule in different transportation conditions. Generally, safe shutdown time will increase as the throughput, temperature at the starting point and environmental temperature increase. Therefore, accurate calculation of safe shutdown time of wet natural gas pipeline is of great significance for safe production and operation.