The invention discloses a Hall thruster discharge channel optimized combined channel structure. The structure comprises an outer ceramic cylinder, an inner ceramic cylinder, a ceramic base and an anode ring; the outer ceramic cylinder is a hollow ceramic ring; the end surface of one end of the ceramic cylinder is step-shaped; the inner ceramic cylinder is a hollow ceramic ring; the end surface of one end of the ceramic cylinder is step-shaped; the ceramic base is a ceramic ring with U-shaped cross section, and includes three parts of an outer ring, an inner ring and support bottom; and the outward end surfaces of the outer ring and the inner ring are step-shaped. The combined channel structure is adopted; an annular discharge channel consists of three parts of the ceramic base, the inner ceramic cylinder and the outer ceramic cylinder; insertion matching parts for guaranteeing guidance and positioning are adopted between the inner and outer ceramic cylinders and the ceramic base; the inner and outer ceramic cylinders are convenient to replace; a thruster has no need to disassemble without introducing disassembly errors; and the test comparison precision is improved.