The invention relates to a skid-mounted waste heat power generation system for an offshore platform main power station. The waste heat power generation system for the offshore platform main power station is characterized in that an oil outlet of a heat conducting oil expansion tank in the waste heat power generation system is connected with an oil inlet of a waste heat boiler through a heat conducting oil circulation pump; the main power station is connected with an air inlet of the waste heat boiler, and the waste heat boiler is connected with a superheater; an oil outlet of the superheater is connected with an oil inlet of the heat conducting oil expansion tank sequentially through an evaporator, a first preheater and a second preheater; a liquid outlet of an organic medium expansion tank is connected with a liquid inlet of a heat regenerator through an organic medium circulation pump, a liquid outlet of the heat regenerator is connected with the superheater sequentially through the second preheater, the first preheater and the evaporator, the superheater is connected with an expander, and the output end of the expander is connected with a power generator through a gear box; and an exhaust port of the expander is connected with an air inlet of the heat regenerator, the heat regenerator is further connected with a liquid inlet of a seawater condenser, and a liquid outlet of the seawater condenser is connected with a liquid inlet of the organic medium expansion tank. The skid-mounted waste heat power generation system can be widely applied to the offshore oil-gas field development project.