Waterproof splice board and waterproof splice device

A water proof splice board comprises a splice main body and two extension bodies. The splice main body comprises a groove-like water guiding part, and an obliquely erected water baffle arranged at the upstream end of the water guiding part. The water guiding part has two parallel first and second sides. The extension bodies are extended outwardly from the first side and the second side of the water guiding part of the splice main body outwards, respectively. The disclosed waterproof splice board can be conveniently installed in the gaps of existing corrugated sheets and provides functions of waterproof and leakproof.