The invention relates to a thidiazuron which is taken as an active matter for the preparation method and application of the product of the quality improvement and production increase of the plant; the content of the thidiazuron in weight percentage is from 0.01 percent to 20 percent, or which in weight volume percentage is from 0.01percent to 15 percent, the others are carriers. The utility model can be made up into liquid preparation and solid preparation. The liquid preparation in weight volume percentage is from 0.01 percent to 15 percent; the thidiazuron content of solid preparation in weight percentage is from 0.01 percent to 20 percent. The thidiazuron which is taken as the active matter for the product of quality improvement and production increase of the plant can be applicable for the plant, the seed of the plant or the medium for the growth of the plant. The invention can be used for the fruit trees such as grape and apple tree; the vegetables such as pumpkin and cucumber; the cash crops such as tobacco and cotton; the oil plants such as rapeseed and peanut; the grazing such as clover blossom; the grain crops such as wheat and corn; and the grafts for various fruit trees. The invention has the advantages that: 1. the invention has the functions of quality improvement and production increase, and can enhance the using effect of the active matter; 2. the invention can used in the mix between the medicaments in different action mechanism, which ensures the using effect of the product; 3. the invention improves the safety, and prevents adverse effects to the crops. Thereby the invention can bring more direct beneficial effects for the vegetable(fruit) farmers.