Objective: Studying the enzymatic characteristics of pathogens can indirectly understand the pathogenic ability of pathogens to the host under different conditions. Methods: The composition and transmission electron microscope observation of the olecranon peach infected by the strain Bacillus velezensis zk1 before and after were investigated. The effects of temperature, pH and metal ions on the enzyme activity were studied by using a single substrate induced by the production of amylase, cellulose, pectinase and xylanase in the strain. Results: After being infected by the strain, the olecranon peach tissue cells were damaged, and the contents of starch, cellulose, hemicellulose and pectin were decreased. The results of enzyme characteristics showed that the optimum reaction condition of amylase secreted by this strain was 60 ℃, pH 7, and 0.15 mmol/L Mn²⁺ could inhibit the amylase activity. The optimal reaction condition of cellulase was 60 ℃, pH 6, and 0.15 mmol/L Mn²⁺ could also inhibit cellulase, and that of xylanase was 40 ℃, pH 8, with various metal ions as activators. The optimal reaction conditions of pectase were 50 ℃, pH 6, and Mn²⁺ had the best activation effect. Conclusion: Bacillus velezensis zk1 is a spoilage bacterium, which is harmful to the postharvest storage of olecranon peach. It causes the decay of fruit flesh tissue by secreting amylase cellulase pectase and hemicellulase. The study on the reaction conditions of these enzymes can provide a basis for the prevention and control of postharvest pathogenic bacteria in olecranon peach in the future.