A novel hybrid energy system driven by torrefied biomass gasification and solar energy is proposed for the first time, and their complementarity to enhance the system’s energy efficiency is analyzed and shown. The system mainly combines biomass torrefaction, biomass gasification subsystem, solar heat collection and absorption refrigeration technology. The effects of different operating parameters on the gasification products were studied. The economic analysis is carried out based on the theory of exergy economy. The results show that torrefaction pretreatment of biomass can significantly improve its fuel quality and gasification performance. With the increase of torrefied temperature, the volume fraction of CO2 and H2 decreased while the volume fraction of CH4 and CO increased. The economic analysis shows that the expected annual income is $72,735, and the investment recovery period is 2.89 years. Through the calculation of the energy-saving and environmental benefits, it can be concluded that the hybrid energy system can save 1.05 × 106 MJ of heat per year. This equates to about 358.26 tons of standard coal or a CO2 emission reduction of 550.59 tons, the participation of solar energy is conducive to the system emission reduction. By tuning the parameter sensitivity, the influence of biomass price change on the unit exergy cost of system products was more obvious.