Cellulose　has　sparked　considerable　interest　in　the　advancement　of　biodegradable　functional　materials　owing　to　its　abundant　natural　sources　and　exceptional　biocompatibility.　This　review　offers　a　comprehensive　review　of　the　latest　research　and　development　concerning　cellulose-based　films,　with　a　specific　emphasis　on　their　classification,　properties,　and　applications.　Specifically,　this　review　classifies　cellulose　according　to　the　various　morphologies　of　cellulose　(e.g.,　nanocrystals,　nanospheres,　and　hollow　ring　cellulose)　and　cellulose　derivatives　(e.g.,　methyl　cellulose,　carboxymethyl　cellulose,　hydroxyethyl　cellulose,　and　cellulose　acetate).　The　subsequent　section　presents　an　analysis　of　cellulose-based　films　with　improved　mechanical　properties,　antibacterial　characteristics,　gas　regulation,　and　hydrophobicity.　A　detailed　discussion　of　the　mechanisms　that　underlie　these　properties　is　provided.　Additionally,　representative　applications　of　cellulosic　composites,　such　as　food　packaging,　medical　supplies,　and　electronic　devices,　are　summarized.　Finally,　the　challenges　faced　by　cellulosic　materials　are　outlined,　and　a　novel　and　feasible　prospect　is　proposed　to　accelerate　the　future　development　of　this　material.