A novel mutual-injection phase-locking fiber laser combination technology based on corner-cuber was proposed. The phase-locking principle was theoretically analyzed and two coherent combination schemes respectively utilizing spherical corner-cuber and planar corner-cuber were introduced. The mutual-injection phase-locking coherent combination experiment of two fiber lasers based on planar corner-cuber was demonstrated, and the locked wavelength centered at 1085.22 nm, the steady interference strips with visibility about 0.5 and the line-width of compression of 44% are experimentally observed. The combined output power is more than 2.4 W with a power combination efficiency of 120%. The relationship between the wavlength shift and the injecting power is found to be in the inverse proportion pattern for two fiber lasers with different injecting power ratio.