Dual-wavelength lasers in the EUV (extreme ultraviolet) band can be applied in many fields such as high-resolution imaging, EUV nonlinear optics, and high-density plasma diagnostics. In this paper, the 46.9 nm and 69.8 nm dual-wavelength laser of Ne-like Ar (Ar⁸⁺) ion pumped by capillary discharge has been obtained. In order to realize to change the amplitude of the main pulse current over a wide range, several parameters of the main pulse power supply such as charging voltage of the Marx generator, the conduction voltage of the spark gap switch, and the conductivity of the deionized water in the Blumlein transmission line, have been adjusted to vary the amplitude of the main pulse current from 8.4 kA to 15.8 kA. On this basis, the influence of the initial argon pressure and the main pulse current amplitude on the intensities of 46.9 nm and 69.8 nm lasers were studied. The experimental results show that there is an optimum pressure under every main pulse current amplitude. The optimum pressures for 69.8 nm laser are lower than those for the 46.9 nm laser. Based on the variation of laser intensity with the initial pressure and the main pulse current amplitude, the optimal experimental parameters for the 46.9 nm laser are current of 10.9 kA and initial pressure of 18.1 Pa and those for the 69.8 nm laser are current of 14.5 kA and initial pressure of 18.5 Pa. When the main pulse current amplitude is 14.5 kA and the initial pressure is 18.5 Pa, the dual-wavelength laser with both strong 46.9 nm and 69.8 nm laser can be obtained. The different influencing rules of the initial pressure and the main pulse current on the 46.9nm and 69.8nm lasers can guide other groups to explore the possibility of achieving 69.8 nm laser by using the existing 46.9 nm laser device. Meanwhile, the research on the optimal parameters of 46.9 nm and 69.8 nm lasers is benefit to enhance the energy of lasers and expand their application fields. One of future studies will focus on the applications of the dual-wavelength laser in sum frequency and difference frequency of EUV lasers.