The invention discloses an acrylate-type poly-chain transfer agent as well as a preparation method and an application of the poly-chain transfer agent in the preparation of a columnar polymer brush. The acrylate-type poly-chain transfer agent is prepared by synthesizing a main chain containing bromine (or chlorine) functional groups by virtue of RAFT and then introducing disulfide ester functional fragments by virtue of a one-step method. The columnar polymer brush is synthesized from the obtained acrylate-type poly-chain transfer agent by adopting a synthesis strategy of 'grafting from main chain' through the RAFT method, homopolymer and block copolymer containing multifunctional branched monomers can be obtained, namely, a brush-shaped homopolymer and a copolymer are obtained. The main chain of the polymer molecular brush is a (meth) acrylate polymer and the side chain of the polymer molecular brush is polystyrene, poly(meth)acrylate and poly(meth)acrylamide or a copolymer thereof. By the preparation method, the tedious steps used in the synthesis of a complex chain transfer reagent are avoided, the pollution caused by the tedious steps is decreased, the synthesized columnar polymer brush has a controllable structure and the preparation method provides a more simple and efficient method to synthesize the functional columnar polymer brush.