The invention belongs to the technical field of modification of natural high polymer compounds and discloses a polysiloxane-modified cationic polysaccharide compound as well as a preparation method and application thereof. The preparation method comprises the following steps: carrying out a cationic modification reaction between a polysaccharide compound and a cationization agent, performing polysiloxane modification with active polysiloxane, or simultaneously performing cationic modifier polysiloxane modification on the polysaccharide compound, neutralizing and drying, thereby obtaining the polysiloxane-modified cationic polysaccharide compound. The product has the advantages of high water dispersibility and drifting difficulty of powder. In addition, due to the introduced polysiloxane, the application performances, such as softness and smoothness, of the cationic polysaccharide compound can be improved to a certain degree, and the polysaccharide compound can be applied to daily care products.