The invention relates to a method for assessing transformer substation communication device grounding body potential rising. The method comprises the following steps that a transformer substation main wiring diagram model is established, the earth current of a transformer substation wire-outlet rod tower under the action of thunder and lightning is determined, a transformer substation grounding grid model is established, the potential of each node of each frequency of the grounding grid model is determined, and the potential difference of any two of the nodes of the grounding grid model is determined. The method provides the basis for the grounding mode design of cables between transformer substation communication devices and provides the theoretical basis for the communication device design protection measures.