Abstract: In order to get the controllable, uniform, tiny and precise droplet in the metal droplet deposition manufacturing, the metal droplet with pneumatic drop-on-demand generator has been developed. The generator consists of the droplet generator, the temperature controller, the pulse pressure controller and low oxygen concentration chamber. When the oxygen concentration is less than 14.2mg/m³, the spray experiment was conducted using developed generator to inject the alloy with 60%Sn-40%Pb. The result shows that the system can get controllably the uniform metal droplet and respond to each pressure pulse through adjusting the parameters of supply pressure, solenoid valve opening and closing time, ball valve opening angle and the pulse frequency.