The current signals of fusion magnet power supply equipment are susceptible to electromagnetic interference, thereby affecting the stability of the power supply system. Moreover, the concurrent operation of multiple power cabinets results in the susceptibility of power signals to the admixture and overlapping of electromagnetic noise with the signals. In addressing the limited denoising efficacy of a single wavelet transform algorithm when noise and signal overlap, this paper proposes an adaptive filtering approach based on wavelet transform. Building upon the initial wavelet denoising of the raw signal, a secondary filtering method for noise is employed through an adaptive filter. Additionally, a variable step size approach is introduced to enhance the convergence speed of the algorithm. Finally, the effectiveness of the proposed method is substantiated through simulation and experimentation.