An extended combined module power socket and an application thereof. The extended combined module power socket comprises a single socket, a plugging part in the socket and a power connecting line. A first extended module socket (2) and a second extended module socket (3) are respectively connected to two sides, i.e. the left side and the right side, of a main module socket (1) in the manner of plugging; a plurality of extended module sockets are respectively connected to the right side wall of the first extended module socket and the left side wall of the second extended module socket in sequence in the manner of plugging; the matching design of slots of each module is achieved using the central symmetry of a parallelogram, and the modules move in the directions of the slots; an insulating cover plate (4) which is connected in the manner of plugging is provided on the side wall of the last socket of the plurality of extended module sockets; and three jacks, i.e. the upper jack, the middle jack and the lower jack for a ground line (10), a live line (11) and a null line (12) are provided in grooves which are connected in the manner of plugging at two sides, i.e. the left side and the right side, of each of the main module socket and the first and second extended module sockets at the same distance, and flat spring bidirectional sliding power contacts are provided in the three jacks. The main module socket, the plurality of extended module sockets and bottoms of the shells of the insulator cover plates are provided with a plurality of locating rod locking mechanisms (8). The combined module power socket has a simple structure, is convenient to use, has security and reliability, reduces the number of contacts, is free and convenient to combine and move, and solves the problems of forward and reverse installation and disassembly and power wiring using the central symmetry of a parallelogram; and in each set of sockets, according to demands, the shapes and number of sockets can be combined freely, and the modules can be moved, added and reduced with the movement, addition and reduction of electrical appliances.