The invention provides a 3D (3-dimensional) printing device, which comprises a case, a
crucible, a cover plate, a liquid conveying device, a pressure conveying device, an outer
spray nozzle, a first
temperature control device, an industrial control device, a second
thermocouple, a second heater and a second
temperature control instrument, wherein the
crucible is arranged in the case; the cover plate is fixedly arranged on the top of the case and seals the
crucible; the liquid conveying device and the pressure conveying device are communicated with the crucible; the outer
spray nozzle is fixedly arranged at the bottom of the case; the first
temperature control device is used for controlling the temperature of liquid in the crucible; the second
thermocouple and the second heater are arranged in positions, near an outlet, in the outer
spray nozzle; the second temperature control instrument is connected with the second
thermocouple and the second heater; a slide block is also arranged in the outer spray
nozzle, and is connected with a first motor; the outlet can be opened or closed through the slide block being driven by the first motor, and the first motor is electrically connected with the industrial control device. The heater is used for heating, so that the concentrated liquid flow is enabled to be in a high-temperature state, and the spray
nozzle outlet blockage due to liquid cooling condensation is avoided; an air film passage restrains the concentrated liquid flow, and prevents the concentrated liquid flow from contacting the spray
nozzle, and the spray nozzle is further prevented from being blocked.