The invention relates to a liquid-cooled case through which cooling water channels run. The liquid-cooled case comprises a main case body, the main case body comprises four panels which are water channel boards; the water channels of the respective water channel boards mutually communicate with each other; the main case body has a water inlet and a water outlet, and is connected with the water channels that penetrate through the water channel boards; each water channel board is welded and sealed by friction stir welding; the main case body is welded by friction stir welding; the through holesof the side water channel boards are machined by a machining method; the water channels with closed through surfaces are welded by friction stir welding; a corresponding engagement slot or mounting surface is arranged inside the main case body and is used for assembling a cooled electronic device. The liquid-cooled case, by reasonably designing a water channel through hole structure and a machining sequence and by using the advantages of low welding deformation, large welding thickness and small weld defects of the friction stir welding, realizes the communication of the cooling water channelsof the chassis, solves the water leakage and the poor reliability of a conventional case, has a reliable manufacturing method and an excellent cooling effect, and is the first choice for integrationand cooling of electronic equipment.