A laser array combining device, which comprises: a laser gain medium array, comprising at least two laser gain units, and each generates a laser beam; a shaping optical system, optical shaping to the laser beams generated by the laser gain medium array, the shaping optical system comprises: a fast axis collimating lens, arranged at an emergent side of the laser gain medium array; a field flattening lens, arranged at an emergent side of the fast axis collimating lens, correcting the field curvature of the shaping optical system; a negative lens, arranged at an emergent side of the field flattening lens; a cylindrical lens, arranged at an emergent side of the negative lens for collimating the laser beams; a dispersing optical unit, arranged at an emergent side of the shaping optical system for diffracting incident laser beams; a partial reflection optical unit, receiving laser beams emitted by the dispersing optical unit.