Disclosed is a grid external surface stable floating body, in particular a grid external surface stable floating body which has a grid or concave-convex polyhedrons capable of absorbing and isolatingwaves on the outside surface and can stay stable in waves. The grid external surface stable floating body consists of a floating body and a grid external surface or concave-convex polyhedrons capableof absorbing and isolating the waves. The floating body provides buoyancy for the grid external surface stable floating body. The grid on the external surface of the floating body blocks the conduction of sea waves on the external surface of the floating body, and a sable static water layer which does not accept the conduction of the sea waves is formed in the grid of the external surface of the floating body. The concave-convex polyhedrons on the external surface of the floating body can change the directions of counterforce buoyancy of wave upwelling on the floating body and a force of gravity on floating body to be no longer on the same straight line, or change action points of the forces to be no longer the same, or change both the action directions and action points of the forces to be no longer the same, and so the counterforce buoyancy and the gravity are not a pair of equilibrant forces and the conditions of Archimedes' s buoyancy law are not applicable. The floating body floating in the waves are not affected by the waves and can keep stable.