A novel antireflection all-fiber laser is presented. The oscillator-amplifier integration is utilized to suppress the effect of the reflection light on the stability of the fiber laser, and obtain efficient output with high power and beam quality. The fiber laser system is set up. The output power more than 2 kW with an optical-optical efficiency of 81.6% is obtained, and the beam quality M2 is better than 1.4.The high-reflected metal is used to verify antireflection ability of the laser. The experimental results show that the system has good long-term stability under full power output.