In order to impart leather with multi-functionality and improve its commercial value, composite coating with flame retardant and antibacterial properties was constructed on leather surface by layer-by-layer (LBL) method using biomass materials〔casein (CA), chitosan (CS) , phytic acid (PA)〕and inorganic component magnesium hydroxide (MH) as raw materials. The antibacterial and flame retardant properties of the coated leather were tested. The results showed that the introduction of CS significantly improved the antibacterial performance of as-prepared coatings. When the weight percent of CS was 1.0 %, the coating had excellent antibacterial effect on S. aureus. When the ratio of MH and PA were 1.5 %-0.4 %, impregnated in three layers, the HRR and THR of the coating were reduced by 42.31 % and 40.97 % respectively compared with those of the leather samples without coating, indicating that antibacterial and flame retardant biomass-based coatings was successfully fabricated.