The renewable energy complementary cogeneration system has broad application prospects in the field of regional comprehensive energy utilization. The author proposes a trough solar assisted biomass cogeneration system, which uses medium and low temperature trough solar energy to heat conduction oil, drives absorption heat pump to preheat water in the heating network, saves heating steam extraction and increases power output under the condition that biomass fuel and heat supply remain constant. The EBSILON professional software was used to model and simulate the case unit and integrated system, and based on this, thermodynamic characteristics such as system energy flow and energy loss were analyzed. The results indicate that: under the design condition, 1.78 MWh of solar power can be generated, the photoelectric efficiency is 20.06%, and the photoelectric conversion efficiency can reach 21.60%. Hourly simulation analysis of the whole heating season shows that the total solar power generation generated in five months of the heating period is 1124.30 MWh, and the average photoelectric efficiency is 16.49%.