The invention discloses a feed device of a distributing machine. The feed device comprises a driving motor (1), transmission equipment, a support device, a feed hopper (2) and a material falling hopper (3), wherein the transmission equipment comprises a spiral body (4), a thrust bearing (5) and a U-shaped conveying trough (6); one end of the U-shaped conveying trough (6) is fixedly connected with the driving motor (1); the thrust bearing (5) is connected with a shaft of the driving motor (1); and the spiral body (4) which is a shaftless spiral body is arranged in the U-shaped conveying trough (6), and is fixedly mounted on the thrust bearing (5). The feed device can adapt to different terrain elevation changes within a certain range; the warehousing time of concrete is shortened greatly; the construction work efficiency is improved; the transmission equipment can be cleaned; and the feed device is simple in structure, and convenient to use and maintain.