In recent years, various types of online monitoring devices have been installed in the digitally intelligent cable line system for electrical equipment. However, these online monitoring devices are relatively independent, and the monitored operation data is not comprehensively analyzed. As a result, it becomes challenging to effectively prevent safety accidents. To address this issue, a dynamics safety evaluation model for digitally intelligent cable systems considering coupling effects is proposed. Firstly, the electrical and non-electrical key characteristic parameters of the digitally intelligent cable line system are selected and classified. Secondly, a causality diagram that can be used for safety evaluation is established, and model functions are designed to analyze and build a dynamics flow diagram for the cable system. To determine the variable weights, an interaction matrix is employed, allowing for the establishment of optimal model training parameters. Failure probability functions are constructed for different types of variables and devices. Additionally, the safety evaluation of the entire cable system is achieved through a tandem model, which is transformed into a system dynamics equation to create a safety evaluation model for the digitally intelligent cable system. Finally, the safety state of a regional cable line is evaluated. The results demonstrate that this model effectively handles complex cable systems by considering the coupling effects between multiple variables. It enables a comprehensive safety evaluation of digitally intelligent cables and ensures their reliable operation.