The invention relates to a universal modular connection structure of an electrical line and a power line, and an application thereof. The modular connection structure is an end surface of two modules in mutual connection, is a power transmission connection end surface of the two modules and is also an electrical connection end surface of the two modules. Power transmission connection comprises spindle sleeve connection, shaft coupling connection, gear engagement connection or synchronous belt connection. Electrical connection is socket connector or wiring terminal connection. The modular connection structure is used for application to a robot. The modular connection structure realizes power transmission and electrical line transmission and is the foundation for realizing modularization of mechanical equipment.