An irregular topology generating method for a network-on-chip is disclosed, belonging the design field of the Internet-on-chip, characterized in that the method comprises the following steps of: dividing nodes in a communication diagram that describes the application of the network-on-chip into a plurality of sets; forming new nodes by using an edge router to connect all the nodes in each set, inorder to form the new directional communication diagram; performing integrated division to the new directional communication diagram until a new set is unable to form or the number of the nodes is less than or equal to 5; then determining the number of core network routers and generating the core network according to the number of the nodes in the finally-formed communication diagram; simplifyingthe network by reducing the redundant edge routers. The invention has the characteristics of small area and low consumption in communication power on condition of meeting the communication demands ofspecific application.