Cantilever support means

Disclosed is a cantilever beam support device. The cantilever beam support device is provided with an upper support box structure, a base support box structure and a hydraulic control device. The inner wall of the upper support box structure is provided with a convex slide rail, the outer wall of the base support box structure is provided with a concave slide rail, the convex slide rail of the upper support box structure is embedded into the concave slide rail on the outer wall of the base support box structure, and a group of hydraulic cylinders are installed in the base support box structure and connected with the hydraulic control device. According to the cantilever beam support device, a cantilever beam can be changed into a simply supported beam in the process of overhanging to the maximum degree, force conditions of the drilling platform cantilever beam are improved, carrying capacity of the cantilever beam is improved, and rated lifting capacity of a derrick is achieved; support height can be automatically adjusted so that support force of the cantilever beam can be kept constant; meanwhile, the area of a well mouth, covered by a drilling platform, can be enlarged after the drilling platform is placed in position, and use ratios of a reserved well mouth of an offshore platform are improved.