The construction trestle is generally designed by using manual calculation method. The design standard of the manual calculation method depends on checking qualifying of each component. The calculation of and analysis on integral forcing of trestle are limited. In this paper, the MIDAS Civil finite element software is brought in, so as to rationalize the steel trestle structure design of invert construction of Hongtashan Tunnel. After many times of adjustment and calculation, a feasible construction trestle is designed and established, and it is proved to be rational.