The noise problem of substation boundary is attracting more and more attention. Traditional manual monitoring is more and more inadaptable to the needs, and the demand for online monitoring is overgrowing. However, the existing relevant standards are not entirely applicable, so there are no unified norms. This article discusses the necessity of online monitoring of noise at the station boundary, the interference of environmental noise on the measurement, the installation of measuring points, and the choices of equipment power supply and data transmission. The discussion has a reference value for the implementation of online noise monitoring in substation boundaries.