The present invention provides a class of isoindolone-imide ring-1,3-dione-2-ene compounds, a preparation method, pharmaceutical composition and use thereof. Specifically, the present invention provides a class of compounds of the following formula (I) or a pharmaceutically acceptable salt thereof, wherein Ar is an isoindolinone-imide group represented by the formula (II); L is absent or is a divalent, trivalent or tetravalent linking group; and X is a group represented by the formula (III). Definitions of the other groups are as described in the specification. The compounds of formula (I) are a class of autophagy modulators, particularly mammalian ATG8 homolog modulators.