The invention belongs to the technical field of genetic engineering and discloses a new method for xylanase secretory expression in escherichia coli. A signal peptide is fused to the N terminal of a xylanase gene, meanwhile, a codon of an encoding histidine tag is added to the C terminal of a xylanase gene sequence, and a target gene nucleotide sequence Signal peptide-Xylnase-6*His is obtained through PCR product recovery; in a target gene cloning and expression vector pET28a, a correct recombinant expression vector is obtained through sequencing; the recombinant expression vector is convertedto a escherichia coli strain; IPTG is added into a sample, and induction culture is carried out on the sample; efficient secretory expression of xylanase is achieved. According to the method, xylanase can be directly secreted into a culture medium; compared with original escherichia coli intracellular expression or yeast secretory expression, the high activity of xylanase can be ensured, the operation is easier, more time is saved, and the cost is lower.