The invention relates to the field of oral cavity care, in particular to a composition for oral cavity care and application thereof. The composition for oral cavity care comprises (i) at least one water-insoluble inorganic magnesium salt whisker component with an available content and a structural formula (1) shown as aMgXx.bMgzYy.cH2O(1) and at least one stilbene compound component with an available content and a structural formula (2), (ii) a thickening system composed of vegetable glue water-soluble salt of cellulose ether, (iii) an antibacterial system composed of modifier protein and sequoyitol and (iv) water. The composition has good viscoelasticity, can be applied to a testee with a higher stripping amount so that the testee can experience nearly-sufficient functions, streptococcusmutans and other harmful bacteria in the oral cavity are effectively inhibited, the tooth wear is retarded, the wear resistance of the teeth is improved, enamel is supplied, the occurrence of decayedteeth is prevented, and the composition can also be used for removal of ulcers or wounds in the oral cavity.