In order to solve the problem that the drum-shaped inaccuracy of the cutting workpiece increases due to the weak rigidity caused by the lengthening of electrode wires between electrodes in reciprocating WEDM with high thickness,a dual-guides device with adjustable spacing was designed.Two circular hole guides were adopted in the device,and the spacing between the two guides was adjustable.The modal analysis and random vibration deformation analysis of the electrode wire between electrodes were carried out by using the finite element method.The results show that compared with the single-guide device,the dual-guides device increases the natural frequency of the electrode wire between electrodes by 18 Hz,and the random vibration amplitude of the electrode wire is reduced to one seventh of the original.This shows that the dual-guides device improves the rigidity of the electrode wire,and the vibration amplitude of the electrode wire is greatly reduced.Finally,the cutting tests of 400 mm high thickness workpiece with two kinds of guides were carried out.The results show that the stripes on the workpiece surface cut by dual-guides device are significantly reduced,and the drum-shaped inaccuracy of the cutting workpiece is reduced by 5.4 μm.It shows that the stability of electrode wire space position is significantly improved by using of dual-guides,thereby improving the cutting surface quality of high thickness workpieces and reducing the drum-shaped inaccuracy of cutting workpieces.