The invention provides a raw material conveying device for a methane tank and belongs to the technical field of agricultural equipment. The problem that raw materials fermented by existing methane tanks are stirred not uniformly enough is solved. The raw material conveying device for the methane tank comprises a material cutting cylinder, a conveying passage and a mixing drum. The mixing drum is a hollow cylindrical structure, and the bottom of the mixing drum is provided with a rectangular discharge port. A rotary plate is arranged in the inner chamber at the other end of the mixing drum. The rotary plate and the mixing drum are concentrically arranged. Several stirring shafts, which are arranged in a ring array with the center line of the mixing drum as the center, are rotatably connected onto the rotary plate. Strip-shaped stirring plates, which can be always horizontally arranged, are fixedly connected onto the stirring shafts. The mixing drum is provided with a driving structure which is used for driving the rotary plate to rotate around the center line of the mixing drum. By the device of the invention, raw materials inside the mixing drum can be lifted from bottom to top, and after moving to the upper part of the mixing drum, the raw materials are extruded by the upper wall of the mixing drum to gradually fall downwards. Therefore, efficient stirring and uniform mixing are realized.