The invention relates to a high-solubility photochromic compound and a preparation method thereof. The high-solubility photochromic compound has a structure as shown in a formula I. In the formula, R1, R2, R3 and R4 are the same or different and independently represent hydrogen, C1-C6 alkyl, C1-C6 alkoxy, C1-C6 alkyl alcohol, halogen, trifluoromethyl, phenyl, morpholine, piperidine or indole, R5 represents an alkyl group of C1 to C6, an alkoxy group of C1 to C6 or an alkyl alcohol of C1 to C6. R < 6 >, R < 7 > and R < 8 > are the same or different, at least one of theR < 6 >, R < 7 > and R < 8 > is-O-(CH2CH2O) m-Z, and the rest of theR < 6 >, R < 7 > and R < 8 > is hydrogen, C1-C6 alkyl, C1-C6 alkoxy, halogen, trifluoromethyl, phenyl, morpholine, piperidine or indole; m represents an integer of 0-6; z represents hydrogen or-(CH2) p-CH3; and p represents an integer of 0-6. The invention also provides a preparation method of the compound, and the prepared compound shows excellent compatibility in an organic solvent system or a polymer system, has the characteristics of rapid photoresponse, fast fading rate, good fatigue resistance and the like, and has a good application prospect.