Abstract: With the continuous improvement of satellite application level,the application power of satellite-based microwave SSPA (solid-state power amplifier) is increasing, and the current carrying capacity of the SSPA circuit has put forward more stringent requirements. Based on the analysis of the satellite-based microwave SSPA circuit, this paper proposes a new composite film layer structure to enhance the current carrying capacity of ceramic-based microwave solid-state circuits, and conducts detailed tests on the line width accuracy, surface resistance, film adhesion and other process indicators and current carrying capacity of thin-film circuits made based on this film layer structure. Compared with the traditional film layer structure, this composite film layer structure can significantly enhance the thermal conductivity of circuit lines and improve the current carrying capacity and application reliability of solid-state circuits.The test results show that using NiCr-Au-Cu-Ni-Au composite film structure, the circuit on high-purity alumina substrate can work stably at 9A current(the same result for surface film layer integrity and obvious surface scratches) ,0.4mm lines on high dielectric constant substrate can withstand 5A current, film control range 10-13 microns,100 microns line width precision 15 microns, film adhesion force is greater than 2kg/mm2,25 microns of gold wire destructive bonding tension value greater than 3.5g，250 gold tape microns of destructive bonding tension greater than 100g, to meet the high-reliability requirements of aerospace engineering applications.