To improve the surface quality of multiple cutting and eliminate the recast layer in high-speed wire-cut electrical discharge machining (HSWEDM), a novel combined processing based on diamond wire saw and molybdenum twisted wire is proposed in this paper. This closed-loop tension control system can detect tension to stabilize the spatial position of the electrode wire in real time. Compared with molybdenum wire, experimental results show machining status between gaps are superior, with more breakdown delay. Surface roughness (Ra) is reduced from 0.902 to 0.552 μm with combined processing of the twisted wire. The thickness of the recast layer is also reduced by 62% compared with multiple cutting of molybdenum wire, and the straightness error is significantly reduced.