Due to the presence of harmonics, the noise characteristics of converter transformers differ significantly from those of ordinary transformers. Currently, the mechanism through which harmonics affect noise is not clearly understood, necessitating research on their influence patterns in converter stations. To this end, a monitoring system for converter transformer operating conditions and radiated noise is developed. Through theoretical research, simulation analysis, and noise monitoring data analysis, the characteristics of converter transformer noise under no-load and loaded conditions are summarized. Based on noise data from converter transformers under various load conditions, the noise variation patterns of converter transformers under different loads are elucidated, from which a noise prediction method for converter transformers is derived. The research results indicate that, compared to ordinary transformer noise, the noise of converter transformers under specific load conditions is concentrated mainly at higher frequencies. The high-frequency components of converter transformer no-load noise are primarily generated by the nonlinearity of the core magnetization process and have little correlation with voltage harmonics. The high-frequency components of converter transformer loaded noise are strongly related to current harmonics. Due to the human ear's greater sensitivity to high-frequency noise and the modal characteristics of converter transformers, the A-weighted sound pressure level of 400 Hz noise is the highest and varies significantly and positively with current changes. The A-weighted sound pressure levels of noise at other frequencies show insignificant changes. Based on this characteristic, the derived noise prediction formula has an average error of 0.23 dB, effectively predicting converter transformer noise. The research findings provide guidance for converter transformer noise testing and offer a method for noise prediction of operating converter transformers.