Research conclusions:(1)The diabase is rich in kaolinite, with the engineering properties of low strength, easy disintegration and weak expansion, but it is dilatable along the unloading direction under the unloaded stress path.(2)The distribution of the diabase dikes has the significant effect on the magnitude and distribution of the rock pressure. The pressure of the surrounding rock with exposing more diabase section is bigger than that with exposing less diabase section, and the pressure of the exposing part is bigger than that of the adjacent parts without exposure.(3)The distribution of diabase dikes also affect the tunnel deformation significantly. The settlement of the vault with exposing the section is larger. In the section of exposing the diabase on the dome, the convergence deformation of the sidewall is larger. In the section of exposing the diabase on the sidewall and arch, the tunnel deformation lasts longer. (4) In the section of exposing more diabase, the large tunnel deformation contains the swelling deformation and compressional deformation. (5)This research result can be available for the design and construction of tunnel in diabase zone.