In this paper, phase-locking and coherent output of two fiber lasers is studied. Two Er3+ high-doped fiber lasers are coupled using fused fiber coupler each other. The idea to fabricate a simple resonant cavity by coupled with fused fiber coupler in front of high-reflectivity front surface reflector of fiber lasers is proposed, thus to realize the coherent beam combining of two fiber laser. The mutual-injection phase-locking coherent combing experiment of two fiber lasers was demonstrated, in which the locked wavelength (center wavelength is 1549.8nm, line-width is 0.08 nm), the steady interference strips and the line-width of compression were experimentally observed. The slope efficiencies of the individual laser and the laser array. When reflectivity is 70% and pump power of two fiber lasers is 145mW, the maximum combined output power of 127mW is obtained.