The invention discloses a material-gripping manipulator for light building material processing, and belongs to the technical field of building material processing equipment. The material-gripping manipulator comprises rails, a moving device and a clamp, and the clamp comprises a clamp support, a plurality of clamping mechanisms and telescopic mechanisms. Two clamping mechanisms form a group, and each group of clamping mechanisms is symmetrically and movably connected with two parallel side edges of the clamp support through side face middles. Two ends of the first telescopic mechanism are connected with the top of the clamp support and the moving device respectively, and two ends of the second telescopic mechanism are connected with one end of the corresponding clamping mechanism and the clamp support respectively. Clamping portions are oppositely fixed at the bottoms of each group of clamping mechanisms, are pushed by the second telescopic mechanism to rotate around movable joints of the side face middles of the clamping mechanisms and the clamp support, approach to each other and clamp blanks or building blocks. The material-gripping manipulator can transfer the building blocks repeatedly cut and formed at one step, the workload of workers is reduced, and processing efficiency is greatly improved.