Abstract: To explore the application value of a fully biodegradable film in tobacco planting and evaluate its suitability in crop growth with good thermal insulation and moisturizing effects， this paper analyzed the changes in chemical structure， surface micromorphology， and tensile strength of the fully biodegradable film during the degradation process through field service aging observation and infrared spectroscopy， scanning electron microscopy， tensile mechanical property test， and gel content test. The results indicated that when the fully biodegradable mulch film was served in the field for 51 days， the film surface at the root system of the crop was still intact. This could meet the requirements of the crop mulching cycle. In addition， after the crops were picked and ploughed， the biodegradable film could be degraded in the field under actual environments， and there was no residual film generated.

Key words: fully biodegradable film, tobacco cultivation, field service, degradation