Fertilizer coating system

A fertilizer coating system comprises a shell and a rotating drum located in the shell and capable of freely rotating, a plurality of mixing grooves are evenly and transversely formed in the circumference of the rotating drum, a mixing cavity is formed in the center of the rotating drum, a stirring shaft capable of freely rotating is transversely installed in the mixing cavity, and a plurality of inclined paddles are evenly installed on the stirring shaft. An exchange runner communicated with the mixing cavity is obliquely arranged on one side of the bottom of each mixing tank; a feeding channel is vertically formed in the top of the shell, a spraying pipe assembly is installed on one side of the upper portion of the shell, a turning plate door with the same curvature as the shell is installed on one side of the bottom of the shell, and supporting legs are arranged in the center of the top of the shell. Fertilizer particles not only slide relative to the shell, but also rotate in the mixing grooves, the diffe