The invention discloses a recombinant cell line for stable expression of porcine epidemic diarrhea virus S1 protein, a vaccine and an application. The recombinant cell line is constructed by transfecting HEK-293T cells by virtue of recombinant plasmid which is constructed by carrying a target gene on a lentiviral vector, and then transfecting the HEK-293T cells by virtue of generated high-titer virus particles; and the recombinant cell line, which can achieve stable expression, can still keep an excellent protein expression level after several passages. The recombinant cell line for stable expression of the porcine epidemic diarrhea virus S1 protein provided by the invention has the characteristics of being easy for culture, rapid in proliferation, unlimited in expansion, stable in property and high in protein expression amount; and when the vaccine, which is prepared from the expression protein and adjuvants, is used for immunizing pigs, the generation of a high-titer porcine epidemicdiarrhea virus neutralizing antibody can be induced from animal bodies, and the piglets (the pigs) can resist strong attack of porcine epidemic diarrhea viruses.