Rock foundation trench excavation device and excavation method

The invention relates to the technical field of rock foundation engineering, and discloses a rock foundation trench excavation device which comprises a splitting rod, a water delivery pump, a two-way pump, a slurry discharge pump and a rotary spray head, a water bag, a water delivery pipe and a slurry discharge pipe are arranged in a splitting shell of the splitting rod, and the two-way pump is connected with the water bag through a communicating pipe to inject water into the water bag so as to extrude the splitting shell to split rock; the water delivery pump delivers high-pressure water to the rotary spray head through the water delivery pipe so as to drill and cut rocks, and the slurry discharge pump pumps slag slurry formed after high-pressure water cutting away from a construction area through the slurry discharge pipe. Compared with the prior art, the rock foundation trench excavation device is high in construction efficiency and good in construction precision. The invention further provides a rock foun