The invention belongs to the field of equipment of the three-dimensional printing technology, and particularly relates to a spray nozzle of a tabletop low-melting-point metal three-dimensional printer. The spray nozzle comprises a melting material feeding device, a spray nozzle body, a melting material discharging device, a piston piece, a gas pressure controller, a gas pressure meter and a heating piece; the spray nozzle body is used for storing and spraying out melting materials, a gas pressure bin and a melting material bin are arranged in a spray nozzle shell, the gas pressure bin and the melting material bin are separated through the piston piece, and the gas pressure bin is connected with the gas pressure controller and is used for adjusting gas pressure in the gas pressure bin and gas pressure in the melting material bin; the gas pressure meter is arranged on the gas pressure bin, and pressure value in the gas pressure bin is displayed; and low-melting-point metal is adopted to serve as a printing material, the structure is novel, the gas pressure bin is additionally arranged in the spray nozzle, the pressure in the melting material bin is indirectly controlled through the gas pressure bin, the pressure value inside the melting material bin can be visually reflected, control precision is high, the pressure relief speed is high, the phenomena of excessive printing and material dragging are avoided, the precision of finished products is high, the unnecessary technology is removed, and the printing efficiency is improved.