The invention relates to a garbage power generation system with an external independent reheater. The system involves a waste heat boiler, a steam turbine high-pressure cylinder and a low-pressure cylinder, the garbage power generation system with the external independent reheater is characterized in that the waste heat boiler (1) is connected to the steam turbine high-pressure cylinder (3) through a main steam pipeline, the high-pressure cylinder (3) is connected with the reheater (5) through an external reheater inlet pipeline (4), the reheater (5) is connected to the low-pressure cylinder (7) through a reheater outlet pipeline (6), and an outlet of the low-pressure cylinder (7) is connected with a condenser (8), a low-temperature coal economizer (9), a deaerator (10), and a coal economizer (11) in series. According to the system, the external reheater heats the steam entering a low-pressure turbine by burning fuel, the dryness of the low-pressure steam is improved, the low-temperature corrosion is prevented, and the safe operation of a steam turbine is ensured.