The invention provides a novel tubulin inhibitor and an application thereof. The novel tubulin inhibitor is a series of substituted heterocyclic skeleton-based compounds with colchicine binding sites in tubulins as targets. The compounds have the following structure as shown in the specification, wherein the formula is as shown in the specification; n independently represents an integer of 0-5 under the condition that n is less than or equal to 5; A represents a monosubstituted or polysubstituted group; and the group is selected from H, C1-C20 acylamino, C1-C20 acyloxy, C1-C20 alkanoyl, C1-C20 alkoxycarbonyl, C1-C20 alkoxy, C1-C20 alkylamino, C1-C20 alkylcarboxy amino, aroyl, arylalkanoyl, carboxyl, cyano, halogen, hydroxyl, nitro and methylthienyl.