A modular combined socket, which comprises a circuit module, a connection module and at least two socket modules. The circuit module includes a connection module interface and a socket interface with at least four conductive paths connected to each other. The connection module includes a power supply interface and a circuit module interface with at least four conductive paths that are connected to each other and can be connected to the connection module interface of the circuit module through the circuit module interface, and the socket module includes two or three interconnected socket modules. The output socket and line interface of the conductive path, each of the socket modules can be connected to different conductive paths of the socket interface through the line interface. It has the advantages of flexible combination, large load bearing and strong anti-interference. The present invention also provides a modular power supply assembly.