The utility model provides a suction pipeline switching device for an endoscope. A plunger is inserted into a working cylinder, the plunger can move between a first position and a second position, cover bodies are arranged at the upper end portion of the plunger and the upper end portion of working cylinder, and force is exerted on the plunger at the first position through the cover bodies. At the first position, a first valve body is separated from a first valve seat to be in an opening state, a second valve portion is in seal connection with the second valve seat to be in a closed state. At the first position, a suction pump is communicated with the atmosphere, at the second position, the second valve portion is in seal connection with the second valve seat to be in a closed state, and the second valve portion is separated from the second valve seat to be in an open state. At the second position, a suction pipeline is communicated with the suction pump and can suction. At the second position, a cam follower passes over a cam surface to enable the plunger to be inclined and enables a gap between the second valve seat and the plunger main body to be enlarged.
