Disclosed are a multifunctionalized polyethylene glycol derivative and a preparation method therefor. The derivative has an H-shaped structure as represented by formula (1) and comprises one linear core LPEG and four PEG branch chains, where n1, n2, n3, and n4 respectively are the degrees of polymerization of the branch chains, U1 and U2 are trivalent branching groups connecting the core LPEG to two of the PEG branch chains, F1 and F2 contain a functional group or a protected form R01 thereof and may or may not contain a branched group G, correspondingly, the number of R01 is one or more, F1 and F2 are either identical or different, any one linking group in the molecule or any linking group formed with an adjacent heteroatom group can either remain stable or be degraded, and any one PEG segment in the molecule is discretely polydispersed or monodispersed. The multifunctional polyethylene glycol is flexible and diverse in terms of branch structures and the lengths of branching arms, has various parameters and performance indicators that are adjustable and easy to control, and has a broad applicability.
