Abstract: The simulation and optimization software for Shell coal gasification plant (SCGP) has five main functions，i.e. the coal database building up，the gasifier simulation，the gasifier optimization，the gasification plant simulation and the startup table calculation. The gasifier is simulated by chemical and energy equilibrium model，and the heat transfer of water screen is simulated by empirical model. Results of the software simulation have a good agreement with the real-time operating data from SCGP at SINOPEC Anqing Company，which indicates the software is reliable. The software can be used to the online and offline simulation，optimization，calculation of startup table，et al，which provides a guide to SCGP in achieving safe，stable，long-cycle and optimal operation.