The invention provides an energy-saving silencer, and relates to the technical field of silencers. The silencer comprises a silencer housing and a silencing core arranged in the silencer housing, wherein the silencing core comprises a wind power generator, wind wheel blades of the wind power generator naturally form spoilers, the spoilers are sleeved on a transmission shaft of the wind power generator in a penetrating way to drive the wind power generator to rotate so as to generate electricity. The silencing core, i.e., the wind power generator can directly transmit power to accumulator batteries through a power cord. In the silencer provided by the invention, the silencing core is composed of a plurality of elongated spoilers which are provided with vent holes and are sleeved on the transmission shaft of the wind power generator in a penetrating way, i.e., the wind wheel blades of the wind power generator, exhaust gas is eliminated by sequentially passing through the vent holes of the spoilers, noise generated by exhaust gas can be effectively reduced, and the silencing effect is obvious. The energy-saving silencer has the advantages of small structure, simplicity in manufacture and convenience for disassembly, cleaning and maintenance, not only has silencing and noise reduction functions, but also can generate electricity and provide electric energy. The silencer not only can be used on an exhaust pipe of an engine of an automotive vehicle, but also can be used on exhaust pipes of other internal combustion engines, boilers, tractors, internal-combustion electric generators, aerodynamic equipment, and the like.