Engine emission verifying device

The utility model discloses an engine emission verifying device which comprises a standard mixed gas tank, a standard mixed gas output pipe and an air input pipe, wherein the standard mixed gas output pipe is successively provided with a pressure regulator valve, a needle valve, a flowmeter, a three-way valve and a system pressure gauge, the system pressure gauge is connected with an emission testing system, and the three-way valve is provided with a verification port, an air bypass port and an emission sampling port which are respectively connected with the flowmeter, the air input pipe and the system pressure gauge. The device solves existing problems in the verification process of an engine emission testing system in the automobile industry, realizes online systematic verification for the emission testing system, improves means to emission system verification, simulates the verification process with real sampling, and provides reliable data for engine development and verification.