Abstract: With the increasing demand of urban power load, more and more substations go deep into the city center, the distance between them and residents is getting closer, and the public’s environmental awareness is getting stronger. The noise pollution of Urban Substations has become a hot issue of public concern. In order to solve the problem of disturbing residents caused by excessive noise emission at the boundary of a 110kV indoor substation in urban area, the noise source and noise characteristics of the substation are analyzed. According to the analysis results, the substation adopts noise elimination technology for noise control, that is, installing noise elimination device on the ventilation pipeline of the fan to suppress the aerodynamic noise level and weaken the influence of the cooling system noise on the boundary noise So as to achieve the purpose of substation noise control. The results show that the noise of the southwest and northwest side of the substation meet the standard of "Emisson Standard for Industrial Enterprise Noise at Boundary"（GB 12348-2008）, and the noise control effect of the southwest side is particularly obvious. The reduction amount of the noise of day and night reaches more than 10dB（A）, and the reduction amount of the noise at night at the kindergarten reaches 7dB（A）. It meets the requirements of class 1 standard of "Environmental Quality Standard for Noise"（GB 3096-2008）. The successful implementation of the substation noise control project not only brings good environment to the surrounding residents, but also brings good social benefits. It also provides reference for the noise control of No.3 main transformer and the same type of substation in the final planning.