The present invention relates to a lithium ion capacitor and a formation method therefor. The capacitor has a positive electrode comprising porous carbon and a lithium-intercalated metal oxide and a negative electrode of non-graphitizable carbon, wherein the metal lithium electrode and a cell are arranged oppositely and separated by a diaphragm, a porous current collector is used as a current collector, and during the formation, the lithium-intercalated oxide in the positive electrode is used as a lithium source for lithium intercalation of the negative electrode, and a third electrode lithium plate is used for supplementing lithium ions to the de-lithiated state metal oxide in the positive electrode. The lithium ion capacitor is formed in two steps in the present invention, so that the doping of the negative electrode is more stable, efficient and uniform, thus prolonging the cycle life of the capacitor; moreover, the consistency of the capacitor can be improved, facilitating the assembly of both a module and a system.