Automobile exhaust harmful substance detection device

The utility model relates to the technical field of tail gas detection, and provides an automobile tail gas harmful substance detection device which comprises a bottom plate, a water tank is fixedly mounted at the top of the bottom plate, a suction fan is fixedly mounted on one side of the water tank, an input end of the suction fan is fixedly connected with an elastic hose, and the other end of the elastic hose is fixedly connected with a suction head. Tail gas exhausted by an automobile is collected through a suction head connected with a suction fan, after the tail gas is detected by a detector body, the tail gas is introduced into a coiled pipe and exchanges heat with water in a water tank, and heat in the tail gas is recycled; the two clamping blocks move relatively to drive a trapezoidal block at the top of a driving plate, so that the driving plate moves downwards on a limiting rod, an anti-skid plate is in contact with the ground under the action of a guide rod, the use stability of the equipment is i