In this paper, a method based on time domain response and superposition principle of heat conduction field is studied in this paper. It can realize the quick calculation of transient temperature rise of direct buried cable. The combined action of cable groups is discrete as a combination of multiple cables alone. Self — heating of a single cable can be described by a self — response model. The mutual influence between the cable can be described by mutual response model. And then the integrated temperature rise of the cable core can be obtained through node temperature rise coupling method. So the fast calculation of the transient temperature rise is realized. In the example verification, the model parameters are extracted by using the common software CYMCAP. And then the transient temperature rise process of the typical working condition can be calculated. Finally, compared with the software results, the validity of the method is verified.