The invention discloses a refuse incineration power generating system and method. The system comprises a refuse pit, an anaerobic jar, an incinerator, a waste heat boiler, a biogas power generator, ahigh-speed steam turbine and a power generator. The biogas power generator is provided with a biogas inlet and a second smoke outlet, the biogas inlet is connected with a biogas outlet, the second smoke outlet is connected with a second smoke inlet, the biogas power generator can enable biogas to be burnt for power generation, and second smoke is obtained. The waste heat boiler is provided with afirst smoke inlet, a second smoke inlet and a superheated steam outlet, and the first smoke inlet is connected with the first smoke outlet. By the adoption of the system, the biogas is introduced intothe biogas power generator to be burnt for power generation, the power generation amount of a power plant is increased, and then the economic benefits of the power plant are increased; and the secondsmoke is introduced into the waste heat boiler to be reused, heat of the second smoke is fully utilized, and resource utilization of refuse is achieved.