The invention discloses a heat-resisting protective agent, swine fever heat-resisting protective agent live vaccine and a preparation method of the swine fever heat-resisting protective agent live vaccine, and belongs to the field of biotechnology. The heat-resisting protective agent is prepared from the following components: 10-15 percent of cane sugar, 2-6 percent of polyvinylpyrrolidone, 2-4 percent of polylysine, 0.5-3 percent of enzymolysis gelatin, 0.2-1 percent of sodium citrate, 2-10 percent of thiourea, 2-6 percent of bovine serum albumin, 1-4 percent of lubrol and the balance of water. Semi-finished product virus liquid and the heat-resisting protective agent are mixed, frozen and dried to obtain the swine fever heat-resisting protective agent live vaccine. The heat-resisting protective agent is added to reduce the damage to the virus in a freezing and vacuum drying process and improve the stability in the storage and use process of the product. The swine fever heat-resisting protective agent live vaccine prepared from the method disclosed by the invention realizes refrigerated preservation in a storage and transportation process, and a retention period is prolonged to 36 months at the temperature of 2-8 DEG C.