Highway multi-arch tunnel as a new structure form has been developed in resent decades with the rapid development of high level road, and this tunnel structure form has the merits of good adaptability and superiority in the condition of complex land form and difficult line designation. However, compared with individual tunnel and conjoined tunnel,multi-arch tunnel has the question of mother rock's frequent perturbation, construction difficulty, et al. In the geological condition of shallow buried, soft rock, and carst, et al. the mother rock of these kinds of tunnel must be paid attention in the whole construction stage. This paper, taking the Baiguoba Tunnel, Enshi to Lichuan section, Hurongxi express way, as the background and combining field engineering construction, analyzed the Baiguoba Tunnel with MIDAS-GTS, laid the emphasis on surrounding rock mechanics property, drew a conclusion of stress regularity, and put up the countermeasure to the weak part.