Abstract: It is very complex and inconvenient to update application software of hydraulic support control system in underground working face. In order to solve the problem, a scheme of online upgrade based on IAP was designed, and an online download mode of program source codes based on three-stage communication structure was proposed. The code is extracted by explosion-proof computer and sent to the server, then all the support controllers are upgraded by the server. For adapting to underground complex electromagnetic environment, the XRAM store link and data validation link are combined to improve reliability of online upgrade, which can avoid the problem of upgrade failure caused by communication error. A set of HEX file code processing software was developed based on PowerBuilder to achieve automatic code extraction of software.