5G technology is a breakthrough. The next generation of telecom networks (fifth generation or 5G) started hitting the market end of 2018 and will continue to expand worldwide. The increasing sophistication of automobiles has led to the integrating of various electrical equipment into modern cars. These electrical systems often require remote control achieved through 5G communication technology. However, this technology also exposes these systems to various cyber threats. To address this issue, that proposes a Secure Data Transmission Control Method for Electrical Equipment of Automobiles using NB-IoT security modules. The method involves designing a secure data transmission protocol that ensures the transmitted data's confidentiality, integrity, and authenticity. The protocol will be implemented on a 5G communication network using NB-IoT security modules. The protocol's effectiveness will be evaluated based on its security, reliability, and efficiency.