In order to meet the requirements of lightweight， high performance and thermal control function of satellite main structure，this paper studies from the aspects of small satellite cabin structure optimization， load-bearing thermal control integrated design and stand-alone support structure optimization design，and verified by simulation analysis and mechanical test.In this paper，the cabin plate of the main structure of the satellite is optimized by using low density lattice structure，and the cabin plate is directly manufactured as a whole part， which reduces the weight and shortens the development cycle of the small satellite at the same time.The bearing thermal control integrated design of the laser reinforced manufacturing satellite cabin plate is carried out，and the thermal control design such as heat pipe is integrated into the cabin plate to carry out the multidisciplinary optimization design of structural thermal control cooperation.the number of parts and components is greatly reduced， and the integration and lightweight of structural thermal control function are realized. The mechanical simulation analysis and experimental verification of the laser reinforced manufacturing satellite main structure show that the stress of the satellite main structure is less than 140 MPa，and the yield strength of the laser reinforced aluminum matrix composite is about 410 MPa，which still has a large safety margin，which shows that the mechanical properties of the satellite main structure can meet the requirements.The research results can achieve the overall improvement of the performance and functions of the new generation of satellites，such as lightweight，high load bearing and thermal control，directly promote the progress of satellite structure manufacturing technology，and improve economic and social benefits.