The trussed front structure is the important assembly for space solar telescope; compared to the other assemblies on the solar telescope, it can be easily affected by the solar heat flux. Evaluating the influence of optical performance change of trussed front structure for space solar telescope under the external loads is a key technical problem that should be taken care. Opto-mechanical integrated simulation technology as the important method to evaluate the optical performance change under the external loads, it is selected and researched to evaluate change of optical performance for solar space telescope. First, opto-mechanical simulation algorithm is studied and the interface program ISIA is developed based on the research of the algorithm. Second, the correctness validation of ISIA is validated and the validation result demonstrates that the calculation precision of ISIA is higher and to be equivalent to the Sigfit. The ISIA provides the high-precision algorithm and tool support to realize the opto-mechanical integrated analysis of space solar telescope. Third, the optical performance evaluation of space solar telescope under the certain thermal control case is carried out. Based on the opto-mechanical simulation result, the data reference is provided for the structural design of trussed front structure for the space solar telescope. Besides, the environmental adaption design is improved as well for the space solar telescope.