The utility model discloses an impedance composite muffler of a turbocharger. The impedance composite muffler comprises a muffler body, wherein the muffler body is composed of a front wall, a back wall and a cavity formed by the front wall and the back wall. Connecting blocks are arranged between the front wall and the back wall. Fan-shaped grooves are formed in the circumference direction of the front wall and the circumference direction of the back wall at intervals. Two side faces of each fan-shaped block are arranged inside the fan-shaped grooves, wherein noise reduction materials fill the inside of the fan-shaped blocks. The circumference large end of the fan-shaped block is fixed on a pore plate ring. The two sides of the pore plate ring are fixed on the front wall and the back wall, and the outer side of the circumference of the pore plate ring is provided with a filter screen. The outer side of the circumference of an inner cavity is divided by the fan-shaped blocks in the radial direction. A resistance noise reduction air flow channel is formed between the fan-shaped blocks. The center of the cavity is provided with an expanding cavity. The expanding cavity is communicated with a concentrated air flow outlet of the center of the back wall. The front wall is further provided with an oil gas exhaust hole, a temperature measurement hole and a pressure measurement hole. The back wall is further provided with a cleaning water pipe. The impedance composite muffler is used on the conditions of high pressure ratio and mass flow of the supercharger, can effectively reduce the aerodynamic noises of a supercharger and can ensure that the turbocharger can work effectively.