The operating environment and strict process requirements of cracking gas switching valve make its maintenance a key and difficult point in the industry. This paper elaborates on the process characteristics of cracking gas switching valve and the selection and use of switching valve, introduces the structural characteristics and sealing principle of cracking gas double gate valve, analyzes the key points of maintenance for cracking gas double gate valve, lists the cases of faults caused by improper maintenance, and presents some improvement measures for the maintenance problems.