A variable air exhaust through flow area air 
inlet pressure control type adjusting device for a turbocharged engine belongs to the technical field of 
mechanical design and comprises an 
air compressor, an engine, a 
turbine, a volume cavity, a rotation body, a spring, a rotation rod, a rotation shaft and a rotation plate. The longitudinal sections of the volume cavity and the rotation body are both in arc shapes, the rotation plate is installed in an air 
exhaust pipe, the rotation plate and the rotation shaft are fixed together, the 
left wall of the rotation body is connected with the 
left wall of the volume cavity through the spring, and two ends of the connection 
pipe are respectively communicated with the right wall of the volume cavity and an air inlet 
pipe of the engine. When pressure in the air inlet 
pipe of the engine is high, the rotation body drives the rotation plate to rotate in a counterclockwise mode, pumping loss of the engine is small, and the whole performance is excellent. When pressure in the air inlet pipe of the engine is low, the rotation body drives the rotation plate to rotate in a 
clockwise mode, available energy in front of the 
turbine is more, air 
inlet pressure of the engine is high, and the whole performance is excellent. The variable air exhaust through flow area air 
inlet pressure control type adjusting device for the turbocharged engine is reasonable in design, simple in structure and suitable for a 
turbine single inlet turbocharged 
system.