The invention discloses a combined live vaccine of transmissible gastroenteritis virus of swine (TGEV) and porcine epidemic diarrhea virus (PEDV) and a preparation method thereof. An attenuated swine transmissible gastroenteritis virus HB08 and an attenuated porcine epidemic diarrhea virus ZJ08 which are self-separated, attenuated and stored respectively undergo viral multiplication on ST cells and VeroE6 cells, and seedling and freeze drying are then carried out by adding a freeze-drying protective additive into a virus solution which is qualified after inspected. The two diseases, transmissible gastroenteritis of swine and porcine epidemic diarrhea virus, which are epidemic in clinic at present, can be effectively prevented by the use of the combined live vaccine.