Abstract: The SST (Space Solar Telescope) is designed to obtain its diffraction limit quality with aperture over 1 m. It observes the sun with a small view field of 2.8'1.5' to obtain its high spatial resolution imaging of 0.1-0.15. SST observing the sun directly can receive huge heat flow more than 1 000 W that will lead to unacceptable thermal distortion of the optical components. The sunlight enters into the telescope, which is an intense source of both heat and stray light. Based on the special thermal effect and stray light in the solar telescope, a compatibility analysis of the thermal effect of inner-shield in SST was performed. The relationship between the thermal control design and scatting elimination plan on the inner-shield structures in SST was presented. The objective and method of the compatibility analysis were determined. With the thermal analysis software, the temperature fields were calculated for a series of heights of inner-shield structure. A design of the inner-shield structure was put forward in thermal control terms and the suggestion was put out synchronously, which restrained the inner-shield with the height less than 400 mm. The aims of the optimal design of the inner-shield structure of SST are reached. The thoughts and methods of the optimal analysis are also useful for similar optical telescopes designed for solar observation.