The invention discloses a lithium source active material, a positive pole piece, a lithium ion capacitor and a preparation method thereof, wherein the positive pole piece comprises a current collector, the lithium source active material, a capacitor material, a conductive agent and a binding agent, wherein the lithium source active material is preferably one or more of Li5FeO4, Li6CoO4, Li6MnO4, and Li5FexCo1-xO4; the capacitor material is one or more of graphene, activated carbon, porous carbon and other nano materials; and the weight percentages of the following raw materials as follows: 45-5% of lithium source active material, 85-60% of capacitor material, 8-1.0% of conductive agent and 4-1% of binding agent. The positive pole piece has the advantages of being safe, uniform in lithium intercalation, low in technological equipment requirement, high in operability and the like, and is suitable for batch production.