The invention discloses a signal peptide capable of effectively improving protein secretion efficiency and an application of the signal peptide. The amino acid sequence of the signal peptide is shownin SEQ ID NO.1. The nucleotide sequence for encoding the signal peptide is selected from any of the following sequences: (a) a nucleotide sequence shown in SEQ ID NO.2 or a complementary sequence of the nucleotide sequence; and (b) a nucleotide sequence which is obtained through substitution, deletion or addition of one or more nucleotides of the nucleotide sequence shown in SEQ ID NO.2, has a same function of being used a signal peptide with the nucleotide sequence shown in SEQ ID NO.2, or a complementary sequence of the obtained nucleotide sequence. According to the invention, an expressionvector with the combination of the signal peptide and beta-galactosidase encoding gene/transglutaminase zymogen encoding gene is constructed from a vacillus subtilis homologous protein signal peptidelibrary, the signal peptide capable of increasing the secretion of beta-galactosidase can be screened out, and the secretion expression of the transglutaminase zymogen is realized.