Method for producing diisobutylene and triisobutylene based on isobutylene

The invention relates to a method for producing diisobutylene and triisobutylene based on isobutylene. The method comprises the following steps: placing metal ion modified strong acid cation exchange resin in a polymerization reactor and a catalytic distillation tower; then, a fresh isobutene raw material, a part of reaction products output by the polymerization reactor and a part of unreacted isobutene output by the catalytic distillation tower are jointly introduced into the polymerization reactor for a polymerization reaction, and a part of the obtained reaction products enter the catalytic distillation tower for a polymerization reaction; and finally, conveying the obtained reaction product to a diisobutylene refining tower to obtain diisobutylene at the tower top, and conveying the tower bottom material to a triisobutylene refining tower to obtain triisobutylene at the tower top. According to the method, the metal ion modified strong acid cation exchange resin is used as the catalyst, so that the activit