The invention belongs to the field of solar energy industry, and particularly relates to an agricultural greenhouse top solar panel mounting assembly system based on modern industry, which comprises a greenhouse frame, wherein a support is arranged at the bottom of the greenhouse frame, the bottom of the greenhouse frame is fixedly connected with the top of the support, sliding grooves are evenly formed in the top of the left end of the support, the top of the support is movably connected with the bottom of each sliding groove, supporting mechanisms are arranged in the sliding grooves, the inner walls of the sliding grooves make contact with the outer surfaces of the supporting mechanisms, a solar panel is arranged at the top of the supporting mechanism, the top of the supporting mechanism is movably connected with the bottom of the solar panel, a limiting mechanism is arranged at the bottom of the supporting mechanism, the top of the limiting mechanism is movably connected with the bottom of the supporting mechanism, sliding grooves are evenly formed in the top of the support, the top of the support is movably connected with the bottom of the sliding groove, a connecting mechanism is arranged in the sliding groove, and the inner wall of the sliding groove makes contact with the outer surface of the connecting mechanism.