The invention discloses a mechanical arm type clay 3D printer. The mechanical arm type clay 3D printer comprises a motor, the motor is connected to a delivery pump through a conducting wire, the delivery pump is fixedly arranged above a clay storage device through a fixing frame and connected with a lining plate through a first delivery hose at the same time, the other side of the lining plate is connected with a lining head, the bottom of the lining head is connected with a discharge port communicating with a material collecting cavity in a thread mode, and the discharge port is connected with a printing head body through a second delivery hose. A sculpture is firstly modeled and a path is formed, the 3D printer prints out the material quickly and efficiently according to the modeling path and is convenient, simple and efficient, and the production cycle is saved greatly; through coordination of a screw rod, the lining head and a baffle block, printing materials is convenient to switch, and meanwhile, mixed printing of a plurality of printing materials can be achieved, and the adjustment is convenient; through the arrangement of a rubber sealing sleeve, the sealing of the baffle block and a lining cavity can be guaranteed; and through the improvement of the coordination of a sliding block and a sliding groove, the positioning of the baffle block is relatively accurate.