The invention provides a turbocharger with a variable section, belonging to the field of turbochargers. The turbocharger comprises a turbine shell and a turbine blade, wherein an annular airflow path is arranged in the turbine shell and is provided with a waste gas inlet and a waste gas outlet, the turbine blade is rotationally connected to the turbine shell, a regulation mechanism and a control device are arranged in the annular airflow path, the regulation mechanism is connected with the turbine shell in a sliding manner and is in transmission connection with the control device, and the control device is connected with an engine. The control device is connected with the engine, and by detecting the rotation speed of the engine, the regulation mechanism is controlled to cooperate with different rotation speeds of the engine to regulate the size of the waste gas inlet, so that the sluggish phenomenon of the turbocharger is effectively alleviated, and the supercharged range is wide; as the size of the waste gas inlet can be adjusted, the intervention rotation speed of the turbocharger is low, and the high-rotation-speed power of the engine is strong; and the size of the waste gas inlet can be regulated linearly by the regulation mechanism, and thus power outlet is linear.