A laminating device for composite material includes a laser device, a hot roller assembly which has a first hot roller and a second hot roller, a cool roller assembly which has a first cool roller and a second cool roller, an axial roller-driving unit and a spring force-adjusting unit. The laser device provides a laser beam onto laminating surfaces of two separate composite materials prior to the hot roller assembly. The axial roller-driving unit drives the first hot roller and the second hot roller, and the first cool roller and the second cool roller, to undergo relative movement in a first direction. The spring force-adjusting unit provides spring forcing to the first hot roller and the second hot roller, and the first cool roller and the second cool roller, to ensure further the lamination of the two composite materials.