Antibacterial composite film was prepared by blending fish scale gelatin (SG) and chitosan (CS) as raw materials and lavender essential oil (LEO) as antibacterial agent. The morphology and structure of the composite film were characterized by Fourier infrared spectroscopy, X-ray diffraction, scanning electron microscopy and thermogravimetric analysis, and the mechanical, optical, barrier and antibacterial properties were tested and analyzed. The results showed that LEO was well combined with SG/CS base film. Compared with the SG/CS base film, when the content of LEO was 1%, the composite film had good mechanical strength (26.36 MPa) and the elongation at break increased by 12.96%; The transparency decreased to 70.50%; The water resistance and water vapor barrier performance were significantly enhanced, and the water content, water solubility and water vapor transmittance decreased by 22.48%, 30.49% and 26.03% respectively; The DPPH radical scavenging rate was increased by 247.88%, the oxidation resistance was significantly improved and had a good inhibitory effect on E. coli and S.aureus.