The invention provides a joint optimization method for heterogeneous network user access and time domain interference coordination based on the graph theory, and relates to the technical field of communication resource allocation optimization. In order to provide better overall communication quality of the user, the system capacity of a cellular network is increased. The joint optimization method comprises the following steps: linking a macro base station and a micro base station to a total control center; in a user communication initiation stage, obtaining channel information of the user by the base stations through signaling; determining an optional range of ABSF proportions, and sequentially selecting from small to large; once selecting an ABSF proportion, maximizing a target function by the total control center by user access; selecting an access decision through an improved KM algorithm; and comparing the sizes of the optimal target functions under the ABSF proportions, selecting the maximum proportion as the final time domain interference coordination parameter, and selecting the user access method of the maximum target function as the final access mode. The joint optimization method is suitable for a time domain interference coordination and access control joint user in a heterogeneous network with the coexistence of the macro base station and the micro base station.