Abstract: Vacuum cathode arc source is one of the core parts in a vacuum arc deposition(VAD) rig,which directly influences the overall performance of the coating system.However,the macroparticles(MPs) formed in the working process of a vacuum cathode arc source are one critical obstacle for further expanding applications of VAD.By rational design and application of an external magnetic field,the cathode spots motion becomes controllable,the amount and sizes of detrimental droplets could be enormously reduced,which significantly improves coating quality,hence dramatically prolonged the service life.To obtain high reliability requested by large-scale VAD equipment,theoretical analyses and modelling of the vacuum cathode arc source with an external magnetic field were carried out and the results provide important guidelines on the optimization of VAD equipment.