A wave-dissipating block has a body and a turbine generator assembly. The body has an airway and an overhang. The airway is formed in the body, is substantially J-shape and has an opening communicating with a front of the body and substantially facing upward. The overhang hangs over the airway and has an air window formed in the overhang and communicating with the airway. The turbine generator assembly has a housing mounted on the overhang and has an air channel communicating with the air window, a turbine fan mounted in the air channel and a generator connected to the turbinate fan. Waves can directly pour into the airway with minimized loss of kinetic energy and forms a water column in the airway to effectively suck or push air to passing through the air channel to rotate the turbinate fan to drive the generator to efficiently generate electric power.