The invention discloses a tunnel waterproof plate overlapping process, and belongs to the technical field of tunnel engineering. The problem that in the waterproof layer laying process at the presentstage, waterproof plates are not tightly overlapped, and consequently a waterproof layer is permeated is solved. The tunnel waterproof plate overlapping process is characterized by comprising the following steps: a construction site is prepared; an access road is built in a tunnel, and the width of the access road is 6 m; meanwhile, a drainage facility is built; the access road surface is hardenedthrough C20 concrete; and meanwhile, a water well is drilled outside the tunnel and connected with a water suction pump, tunnel construction internal-size water supply is guaranteed, and the water pump is an NU312-type submersible pump. According to the construction process, the seepage situation in the tunnel construction process can be avoided, unknown water feeding points of the tunnel can also be automatically sealed, and seepage is prevented from being expanded again.