Abstract: PLA ( Polylactic acid ) as the main raw material were blown special resin mixture obtained by twin-screw extruder, and then we blew out of the PBC / PLA multi-component film on film blowing machine. To study the tensile testing and the processing performance we could conclude that when the mass ratio of PLA: PBC: citrate : erucic acid amide: antioxidant (1010) : chain extender agent was equal to 100:20:10:2:0.2:0.5, the processing performance and the mechanical properties are good, and the tensile strength reached to 58.50 MPa, elongation at break reached up to 192.50% , it greatly enhanced the toughness of the PLA; It was found by enzymatic degradation experiment, the degradation of the multicomponent biodegradable films of PBC/PLA gradually increased with the increase of the content of PBC but it didn’t increase too much comparing with the pure PLA.