Abstract: A method for manufacturing composite material by vacuuming and resin injection includes the steps of starting with placing and sealing a fiber substance into a mold. The mold is pumped by a vacuum pumping device, and a pressure tank containing resin is pumped by a vacuum pumping device. After the pressure tank and the mold reaching predetermined vacuum conditions, a valve between the vacuum pumping device and the mold and a valve between the vacuum pumping device and the pressure tank are closed. A valve between the pressure tank and the mold is thus opened. Resin inside the pressurized pressure tank is pushing into the mold. After the mold reaching a predetermined pressure, a heater is turned on to heat the resin and fiber for thermosetting process. The heater is turned off after a predetermined reaction condition being reached, and a cooler is thus turned on to cool the mold.