Abstract: The present invention provides a method for improving a one-time seedling rate of microspore embryoids of Brassica campestris ssp. Chinensis Makino, including the steps of: spraying 6-BA onto a flower bud of a plant; sterilizing the flower bud with alcohol and HgCl2; releasing microspores, filtering and centrifuging to obtain purified microspores; diluting the microspores with a NLN medium, subpackaging into culture dishes, and adding phytic acid; finally, subjecting to heat shock treatment and transferring to culture in the dark until embryoids appear, and then conducting shaking culture; transferring the cultured embryos in a cotyledon stage onto a MS medium for differentiation culture, wherein the culture conditions are: 4° C., 14 h of illumination by blue-red compound light/day, and 14 days of culture; and then continuing to culture under the condition of 25° C. and 14 h of illumination by blue-red compound light/day until seedlings.