Although the industrial experiments "strip mining-face mining" gasifier retreat control gas injection underground gasification process (SMFM-CRIP) have been completed, the existing issues of its rock movement and control become a critical bottleneck restricting large-scale production and application. Moreover, in the SMFM-CRIP process, the essential question of studying the rock movement is to master the high-temperature effect of the surrounding rock around the underground burned area. In view of the lack of research on this fundamental problem, this paper used the indoor experiments, theoretical analysis, and numerical simulation to research high-temperature effect of the surrounding rock around the combustion space area in SMFM-CRIP. The conclusions are as follows: (1) SMFM-CRIP can sufficiently extract the components of carbon in coal and the solid waste such as ash left in the goaf to realize green mining. (2) In the SMFM-CRIP experimental area, the scopes of temperature influence have limits on the mechanical properties of overlying strata on both sides of the coal wall of combustion space area. (3) The temperature influence in the SMFM-CRIP experimental area on the roof, both sides of the coal wall, and the floor of the combustion space area did not exceed 16.7, 8.7, and 13.6 m respectively. These results provide important data and guidance for the future design of SMFM-CRIP's large-scale production.