Abstract: To improve the energy utilization efficiency of biomass, a combined power generation system model consisting of biomass gasification coupled with a solid oxide fuel cell (SOFC) and a micro gas turbine was established, and the rationality of the model was verified. Pinewood was selected as the fuel, and the variation patterns of system output power and power generation efficiency were studied as the air-fuel ratio and moisture content in biomass gasification were altered. Additionally, the impact of the operating temperature of the solid oxide fuel cell on the system was analyzed. The results showed that as the air-fuel ratio of biomass gasification increased, the gasification efficiency, output power, and system efficiency of the coupled power generation system all reached an optimal value. When the moisture content of the pinewood was 6.25%, the system's maximum output power reached 97.74 kW, and the power generation efficiency was 34.3%. Under these conditions, as the operating temperature of the fuel cell was adjusted, the power generation efficiency of the system first increased and then slowly decreased. The system achieved its maximum power generation efficiency of 37.8% when the temperature rose to 1200 °C. Under the same mass flow rate of biomass input into the gasifier, different biomass moisture contents corresponded to a maximum system output power and efficiency. As the moisture content increased, the system output power decreased, but the power generation efficiency increased. At a moisture content of 20%, the maximum output power and system efficiency were 96.57 kW and 40.71%, respectively.