The noise characteristics of metro energy feedback converter were experimentally studied to analyze the main noise source, noise transmission rules and the acoustic performance of the inlet/outlet structure. The outlet resistance muffler was designed specifically and verified by test. The results showed that the fan was the main noise source and the product noise exceeding the standard was mainly caused by the fan noise transmission to the outlet directly. The scheme of outlet resistance muffler could effectively reduce the outlet noise transmission and the noise reduction at the outlet of fan could reach 17.33 dB(A). The relevant research in this paper has reference value for improving the acoustic performance of energy feedback converter and similar products and guiding the noise reduction design of product structure.