As its important role in socialism new village construction,policy crop insurance should bring the small - sized farmers into agriculture risk prevention system.However,because of the particularity of agriculture and agriculture risks and the limitation of manage-technology in crop insurance,actually,most small-sized farmers are excluded from the crop insurance system,which is contrary to the policy goal of crop insurance.Taking Zhejiang province for example, the causes for the existing of this paradox were analyzed and the primary suggestions for the classification of different sized farmers were put forward.