The invention relates to a preparation method for an organic carrier used for an alkene polymerization catalyst. The preparation method mainly comprises the following steps: (1) under a room temperature, adding copolymerization monomer divinyl benzene and methylacrylic acid hydroxyalkyl ester into a dispersion liquid of a saturated carboxylic ester with 4-7 carbon atoms, or adding a third monomerstyrene to obtain a terpolymer; (2) adding a stabilizer polypropylene oxide-polyethylene oxide copolymer under a temperature of 20-50 DEG C, wherein the ratio of the stabilizer adding amount to the monomer total adding amount is (0.5-5):100; and (3) adding a free radical initiator, raising the temperature to 60-80 DEG C, and performing a reaction for 3-12h, wherein the ratio of the initiator adding amount to the monomer total adding amount is (0.5-3):100, performing washing on the obtained polymer to remove impurities, and performing drying to obtain the organic carrier. According to the invention, the specific dispersion liquid and a dispersion polymerization method are adopted, thus the preparation method is simple and environmentally friendly, and the obtained organic carrier has a higher pore volume and a higher average pore size.