Under the dual carbon background, a multi-domain communication architecture was constructed to address issues such as a single communication mode and poor adaptability between business and communication technology in the new power load management system. The key supporting technologies of this architecture were comprehensively analyzed. Additionally, an adaptability evaluation system for business and communication technology was developed based on varying business types and their specific communication requirements. A communication technology adaptation method was proposed, employing the fuzzy analytic hierarchy process (FAHP), the CRITIC method, and Grey Relational Analysis-Technique for Order Preference by Similarity to an Ideal Solution (GRA-TOPSIS). The proposed method facilitates the analysis of adaptability between differentiated business requirements and multi-domain communication technologies. The analysis of case studies indicates that the proposed architecture and the adaptation method offer an effective theoretical basis and solution for selecting multi-domain communication technology for the new power load management system business.