The invention discloses a circulating fertilizer drying device, which comprises a working chamber, wherein a material containing pipe is arranged in the working chamber, the material containing pipe is an annular pipe, one end of the material containing pipe is connected with an external rotating motor, the upper side and the lower side of the working chamber are communicated and connected with acirculating air pipe, the middle part of the circulating air pipe is provided with an air extraction motor, the tail end of the circulating air pipe is communicated with the outer end part of an innercavity of a rotor of the rotating motor, the outer end part of the inner cavity of the rotor of the rotating motor is also communicated and connected with a hot air conveying pipe, the rotating motorand the lower side surface of the working chamber are fixed through a supporting seat, and the top end of the supporting seat connected with the working chamber is provided with a rotating shaft. According to the circulating fertilizer drying device , the rotation and turnover treatment of the materials are matched with a ventilation type drying structure, so that the drying efficiency of the device is improved, and meanwhile, an additionally arranged circulating pipeline structure can fully utilize the heat source.