The invention discloses a real-time monitoring device and method for the weld quality in the electronic beam dynamic welding process. The real-time monitoring device comprises a sensing and acquiringmodule, a signal processing module and a display and analysis module; micro-current signals acquired by the sensing and acquiring module are transmitted to the external signal processing module through a shield cable and an aviation plug on the wall of a vacuum chamber; the signal processing module senses and amplifies the acquired micro-current signals to form voltage signals; and the voltage signals coming out from the signal processing module enter the display and analysis module to be displayed and stored on a computer in real time through a data acquisition card and virtual instrument software Labview. According to the real-time monitoring device and method, an overall system for detecting space charges just above a weld in the welding process is designed, and therefore real-time monitoring of the whole electron beam dynamic welding process can be realized; and different welding defects in the welding process and oscillograms are connected through welding process experiments, so that a criterion rule table of the waveform changes on the weld quality is given, and therefore the weld quality can be accurately judged in details.