The acoustic signals in the operation of low‐frequency transformer have the state information of the body, which can be monitored online by arranging acoustic measuring points. An optimization method for the layout of acoustic measuring points for low‐frequency transformers is proposed in this study. First, a model of the low‐frequency transformer acoustic field is constructed by measuring the environmental size of the transformer acoustic field. Then, the virtual acoustic source measured by the transformer acoustic signal is input into the model, and the time‐varying acoustic pressure in the acoustic field is calculated. Finally, the spectral correlation coefficients between the acoustic signals at the candidate measurement points and the virtual acoustic sources are calculated to evaluate and improve the layout of the measurement points for the low‐frequency transformer. The method in this study was used to improve the layout of acoustic measurement points for the low‐frequency transformer in the frequency conversion station in Hangzhou. The results show that the method can effectively evaluate the monitoring ability of the acoustic measurement points on the overall acoustic state of the transformer in different positions. The study provides a reference for the layout optimization of the acoustic online monitoring device for low‐frequency transformers.