A rotation control type air exhaust pipe outlet area variable device belongs to the technical field of mechanical design and comprises an air compressor, an engine, an air exhaust pipe, a turbine, a volume cavity, a rotation body, a spring, a connection pipe, 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 the 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 the air exhaust pipe. When pressure in the air exhaust pipe in front of the rotation plate 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 exhaust pipe in front of the rotation plate 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 rotation control type air exhaust pipe outlet area variable device is reasonable in design, simple in structure and suitable for a turbine single inlet turbocharged system.