The　basis　for　the　formation　of　protein-polysaccharide　complexes　is　intermolecular　interactions,　including　covalent　and　non-covalent　interactions.　Under　specific　processing　conditions,　proteins　and　polysaccharides　can　be　assembled　together　to　form　multi-scale　complexes　at　the　molecular,　microscopic　and　macroscopic　levels,　driven　by　intermolecular　forces.　Regulating　the　formation　of　the　multi-scale　structure　of　protein-polysaccharide　complexes　for　the　synergistic　effect　of　various　components　is　of　great　significance　for　designing　protein-polysaccharide　complexes　with　specific　or　new　functions.　Beginning　with　an　overview　of　the　interactions　between　protein　and　polysaccharide　molecules,　this　paper　summarizes　the　formation　of　the　multi-scale　structure　of　protein-polysaccharide　complexes　and　their　influence　on　functional　characteristics,　and　discusses　future　prospects　for　the　application　of　protein-polysaccharide　multi-scale　complex　systems,　in　order　to　provide　references　for　the　design　and　development　of　protein-polysaccharide　complex　products　with　excellent　functions.　©　2021,　China　Food　Publishing　Company.　All　right　reserved.