To address the low signal intensity and limited detection sensitivity of traditional femtosecond laser-induced plasma spectroscopy, the high-voltage discharge-enhanced femtosecond laser-induced plasma spectroscopy method has been proposed. Using discharge-assisted femtosecond laser-induced plasma spectroscopy, taking copper element as the research object, this study comparatively analyzed spectral responses under different discharge conditions and the time-resolved spectral characteristics of the entire process. Experimental results indicate that the discharge can enhance the spectral signal intensities significantly. At 7 kV, the intensities of the three spectral lines (Cu II 521 nm, Cu I 578 nm, and Cu I 793 nm) are enhanced by factors of 22, 31, and 36, respectively, compared to those without discharge. Different spectral lines exhibit distinct responses to the applied voltage. Time-resolved spectral analysis indicates that the discharge-enhanced signal primarily originates from the prolonged plasma fluorescence lifetime. This study provides a reference for the development of highly sensitive and stable plasma spectroscopic analysis techniques. This method plays a positive role in advancing the application of laser-induced plasma spectroscopy in related fields such as materials analysis and trace detection.