In order to reasonably determine the feasibility and specific effect of comprehensive support measures such as pipe curtain, fiberglass anchors and MJS on the excavation reinforcement of the triple pilot tunnels method for the construction of double-arch tunnels with large cross-section in weak surrounding rocks, the South Extension of Changjiang Road Project in Suzhou is taken as a basis, and a large-scale 3D finite element analysis software is used to set up the whole process of excavation numerical model for a wide range of reinforcing conditions. Numerical model of excavation is established by using large-scale 3D finite element analysis software under various reinforcement working conditions, and the displacement curve of the simulated excavation process is compared with the measured data in the field to verify the reasonableness of the model, and the displacement and deformation control technology of the excavation of the tunnel construction of the large-section double-arch tunnel with large weak surrounding rock is further proposed based on the results of the study. The results show that: (1) Under different support conditions, the surface displacement and settlement at the same measurement point of the tunnel portal are, in descending order, no support measure, single pipe curtain support measure, pipe curtain and MJS collaborative support measure, pipe curtain and MJS and fiberglass anchor integrated support measure. (2) The three-guide method construction of the continuous arch tunnel, the surrounding rock deformation is dominated by vertical settlement, and the horizontal convergence is smaller. (3) Under the condition of no support, the excavation of the trailing tunnel causes disturbance to the leading tunnel, resulting in larger deformation of the support structure of the leading tunnel than that of the trailing tunnel. (4) Under the condition of comprehensive support measures, the vertical displacement of the surrounding rock of the left and right tunnels is symmetrical as a whole, and the impact of the trailing tunnel on the surrounding rock of the leading tunnel is small, and the deformation of the surrounding rock is well controlled. (5) In the construction of the two-lane connecting-arch tunnel, the maximum arch settlement occurs in the peripheral rock of the top of the main tunnel, and the monitoring of the peripheral rock of the top of the main tunnel needs to be strengthened when the construction is close to this area.