Biogenic amines (BAs) are organic compounds that present in fermented foods. The excessive intake of BAs is harmful to human health. Some enzymes belonging to the multicopper oxidase (MCO) family exhibit the activity of degrading a variety of BAs. Thus, they may have good application prospects in reducing ammonia (amine) hazards levels in fermented foods. It is of great significance to accomplish the secretion of multicopper oxidase for the purpose of modification of enzyme catalytic properties for its industrial production and applications. In this work, the secretion of multicopper oxidase in Escherichia coli was achieved by fusing the signal peptide PhoA to the N-terminal of MCOB from Bacillus amyloliquefaciens with an extracellular activity of 69.8 U/L. Secretory of MCOB was improved by optimizing the induction and secretion conditions. The optimal fermentation conditions for MCOB were determined to be: the induction temperature was 25℃, the IPTG concentration was 0.05 mmol/L, induced when the cell density (OD600) reached 1.0, and 150 mmol/L glycine was added after 6 h of induction. After 40 h of fermentation, the extracellular activity of MCOB reached 238.1 U/L, which was 3.4 times of that before optimization.