Growth promotor composition for making seedlings sturdy of cole and preparation thereof

The invention relates to the technical field of crop cultivation, and relates particularly to a rape seedling strengthening agent and a preparation method thereof. The rape seedling strengthening agent composition comprises 30-55 weight parts of potassium dihydrogen phosphate, 17.5-32.5 weight parts of borax ,16-32 weight parts of 15% Paclobutrazol wettable powder, 2-4 weight parts of zinc sulfate, 1-3 weight parts of manganese sulfate, 0.25-1 weight parts of copper sulfate, and 0.25-2 weight parts of ammonium molybdate 0.25-2. The invention also discloses a preparation method and an application of the rape seedling strengthening agent composition.