A phenyl-containing compound, an intermediate thereof, a preparation method therefor and an application thereof. Provided is a compound represented by formula I or a pharmaceutically acceptable salt thereof, where R1, R2, R3, R4 and R5 are independently hydrogen, C1-C6 alkyl, C1-C6 alkoxy or C(═O)OR8; where R8 is C1-C4 alkyl; R6 is (II), (III) or (IV); and R7 is —OH, —NH2, —NHCH3, —N(CH3)2 or C1-4 alkoxy. The compound has a low critical micelle concentration (CMC) and good dilution resistance and is capable of enclosing an insoluble drug to form a small-molecule micelle having a high drug loading capacity and good stability.