The work aims to summarize the latest advancements in polylactic acid (PLA)-based biodegradable films for food packaging, to address the environmental challenges posed by non-degradable petroleum-based plastics and provide guidance for the further development of PLA-based biodegradable packaging materials. The characteristics of PLA materials and preparation methods of PLA-based biodegradable films for food packaging were introduced. The review specifically focuses on research progress in food packaging applications of PLA polysaccharide-based films, PLA protein-based films, PLA plant extracts and essential oils-based films, PLA nanomaterial-based films, and PLA synthetic polymer-based films. PLA-based composite films maintain biodegradability while demonstrating excellent mechanical properties, physical characteristics, and bioactivity, effectively extending the shelf life of packaged foods. These studies provide theoretical support for developing high-performance multifunctional PLA-based biodegradable films and indicate directions for achieving large-scale industrial production.