The present invention relates to a test device for preparing uniform metallic particles through differential pressure control + electromagnetic disturbance, and relates to a micro-spray device in a jet flow mode. This device provides high-frequency and high-quality preparation for mini-solder balls (such as tin and tin alloy) and other metal particles. The technical solution is that the device includes an electromagnetic force generator, a pressure controlled system, a temperature control system, and a ball forming system. The method belongs to a non-contact direct-drive continuous-jet uniformmetallic particle preparation technology. The high-frequency and high-quality preparation of uniform metal particles is achieved by uniformly matching pressure difference parameters and pulse electromagnetic disturbance parameters (current frequency, current waveform, current amplitude, and magnetic field strength), and thus the method is simple and easy to achieve.