An exhaust back pressure and environmental pressure self-adaption type mechanical regulation device in the technical field of internal combustion engines comprises a compressor, a turbo, an engine, connecting pipes, a volume cavity, a moving body, a through pipe and elastic parts, both ends of the first connecting pipe are respectively communicated with an engine exhaust pipe and the upper wall of the volume cavity, one end of the second connecting pipe and one end of the third connecting pipe are communicated with the lower wall of the volume cavity, and the through pipe runs through the upper and lower walls of the moving body. In the process of engine operation, the moving body can move to the left and the right in the volume cavity; under the plateau condition, the pressure on the right side of the moving body is low, as a result, the moving body moves to the right, consequently, the first connecting pipe cannot be communicated with the second connecting pipe, the air intake of the engine is large, and the power is high; under the plain condition, the pressure on the right side of the moving body is high, as a result, the moving body moves to the left, consequently, the first connecting pipe is communicated with the second connecting pipe, the air intake of the engine is small, and the bursting pressure of each cylinder is low. The design of the exhaust back pressure and environmental pressure self-adaption type mechanical regulation device is reasonable, the structure is simple, and the exhaust back pressure and environmental pressure self-adaption type mechanical regulation device is applicable to the turbocharging systems of engines.