Two typical 220kVfull indoor and half indoor substations were selected as the research objects to study the sound source formation and sound field distribution through SoundPlan software simulation, and to carry out the analysis of excessive noise standard at the station boundary. The analysis results show that for HN-220-a2-9 type full indoor substation, the substation plant boundary noise does not meet the noise emission limit requirements under the current layout conditions. Its main sound source is the axial flow fan noise of ventilation and heat dissipation, which leads to the exceeding of the standard at the factory boundary, and the air volume, quantity and location of the fan need to be optimized. For HN-220-a3-4 semi-indoor substations, the noise at the substation plant boundary does not meet the noise emission limit requirements under the current layout conditions. The general design is mainly due to the axial flow fan is too close to the wall and the number is large, resulting in the factory boundary exceeds the standard, the air volume, quantity and location of the fan need to be optimized. And the high altitude noise near the substation is large, especially the east and west section, if there are high-rise buildings next to exceed the standard, it is necessary to take firewall, sound insulation barrier or sound insulation protection measures for the outdoor main transformer. The conclusions of this paper can guide the substation construction and substation noise control.