Coal is still the main energy resources in our country before the realization of the "carbon peak and carbon neutrality targets". Therefore, it is vital to improve the efficiency of energy utilization. Solid oxide fuel cell (SOFC) is a kind of highly efficient energy conversion device. Coal based SOFC would make the maximum utilization of coal resources and contribute to the smooth transition of energy from fossil to the renewable ones. However, the coal produced by the traditional gasification plant contains ash, sulfur and other impurities, which can not be used as the fuel of SOFC directly. This work designs and simulates the gasification and purification process of coal which is suitable to supply to SOFC, as well as the fuel cell power generation and exhaust heat recovery system. The modules of coal cracking, coal gasification, coal purification, gas cooling and heat recovery, SOFC power generation, tail gas combustion, and hot water supplying are modeled by Aspen Plus software. The electrochemical processes of SOFC power generation and gasification processes are simulated by the Fortran module of software. As results, a suitable gas gasification module with 70.1% gasification efficiency is obtained which can be directly connected to SOFC for power generation . The gas mainly contains 58% CO and 32% H2. It is found that the overall energy utilization ratio of the simulation system can reach 78.58% with 37.54% net power generation efficiency of SOFC and 35.11% hot water efficiency under the proposed working conditions. Through sensitivity analysis, it is found that the use of appropriate fuel utilization rate and fuel flow can effectively reduce the operating cost of the system, and the air excess ratio is as big as possible within the selectable range. The whole process of combined heat and power supply system (IGFC-CHP) based on coal gas SOFC power generation technology is modeled and studied in this work, which is significant to the realization of IGFC-CHP technology.