The invention discloses a D2D communication spectrum allocation method based on a position perception weighted graph, and belongs to the field of wireless communication. The method comprises the following steps: firstly, constructing a heterogeneous network model of a cellular network and a D2D communication shared spectrum, and establishing a signal to interference plus noise ratio SINR of a D2Dreceiving user and a SINR of a cellular user; calculating the unit bandwidth communication rates of the cellular link and the D2D link respectively by using the SINR of the cellular user and the SINRof the D2D receiving user; calculating the system capacity by utilizing the unit bandwidth communication rates of the cellular link and the D2D link, and constructing a D2D resource allocation optimization model in the heterogeneous network by taking the maximized system capacity as an optimization target and taking the threshold that the interruption probability of the cellular user is less thanthe maximum interruption probability and the D2D link spectrum allocation constraint as optimization conditions; and constructing a position sensing weighted graph to optimize the D2D resource allocation optimization model to obtain a resource allocation scheme of each D2D communication pair. According to the invention, the total capacity of the system is greatly improved, and the communication quality of cellular users is protected.