The invention provides a fuel and gas-fired boiler oxygen-enriched combustion smoke nearly-zero-emission power generation system. The fuel and gas-fired boiler oxygen-enriched combustion smoke nearly-zero-emission power generation system is composed of a boiler, an air bellow, an air separation device, a burner, a multi-stage heat exchanger, a recirculating fan, an induced draft fan, a dehydration device, an SO2 separation device, a CO2 capturing device, a N2 separator, a NOx reaction device and the like. The concentration of oxygen of secondary air is changed so as to ensure that fuel and gas catch fire in time, burn stably and burn out, the boiler efficiency is improved, and adaptability of the boiler to loads is enhanced. By recycling water steam, SO2, NOx, CO2 and the like brought by burning smoke of fuel and gas, integrated desorption of harmful gas and trace elements in smoke is achieved; meanwhile, the temperature of exhausted smoke is reduced to approach the atmosphere temperature, nearly-zero emission of burning smoke is achieved, the environment is protected, and maximum utilization of resources is also achieved.