The invention discloses a plant polysaccharide cigarette filter tip and a preparation method thereof. Plant polysaccharide, starch, adsorbent, plasticizer, emulsifier, waterproofing agent and plant protein are blended according to a certain proportion, so that the filter tip is prepared. The preparation method includes the following steps: (a) the starch, water and the plasticizer are blended and stirred, so that modified starch solution is obtained; (b) the plant polysaccharide and the modified starch solution are blended; (c) under certain conditions, the emulsifier, the waterproofing agent and the adsorbent are added into the mixture of the plant polysaccharide and the modified starch solution, and after stirring, the mixture is injected into a long cylindrical mold made of anti-freezing, heat-proofing material and molded; (d) the semifinished product is placed into a freezing environment and frozen, i.e. prefreezing; (e) the semifinished product in step d is placed into a freeze dryer and freeze-dried; (f) the porous composite body is taken out of the mold and deburred, and thereby a filter tip stick is obtained. Material resources are rich, the cost is low, and the three wastes cannot be produced. The performance is good, the filter tip can reduce the nicotine content by 40.2 to 84.1 percent, the tar by 26 to 72.1 percent and the nicotinamide by 20 to 39.2 percent, and after use, waste can be biodegraded.