Atom interferometry has important prospect in the precise measurement and inertial navigation fields. The high-precision atom interferometer has an urgent need for Raman lasers with low phase noise and high output power. A dual-wavelength synchronous injection-amplification Raman laser preparation scheme based on optical phase-locked loop is designed, and the preparation of high-power Raman laser is achieved. The phase noises of Raman lasers before and after amplification are both below －80 dBc@0.01～1 MHz, and the total output power reaches 400 mW, which can meet the needs of atom interferometer based precision measurement.