Covalent adaptable networks (CANs) have recently received extensive interests due to their reprocessability and repairability. Rethinking the libraries of the published CANs, most of them are fabricated by one/two‐component reactions and few cases utilize multi‐component reactions to construct CANs while multi‐component reactions are conductive to tailoring the properties of polymers due to their structural designability and flexible choice of raw materials. A novel kind of dynamic covalent bond named aminoesterenamide is presented through three‐component reaction between acetoacetyl, amine and isocyanate. Aminoesterenamide exhibits thermal reversibility through dissociating into vinylogous urethane and isocyanate. When it is used to prepare CANs, the synthesized polymer networks can be reprocessed many times via the exchange reaction between aminoesterenamides. Moreover, the forming of aminoesterenamide involving three starting components imparts CANs with great freedom to tailor their properties. Therefore, the authors believe this method that utilizes three‐component reaction to fabricate CANs would bring new stories and perspectives to the exploration of new types of CANs. Covalent adaptable networks (CANs) represent a broad class of polymer networks with dynamic covalent bonds (DCBs) embedded in the cross‐linked structure, enabling recyclability. Most of DCBs are fabricated by one/two‐component reactions. To enrich the method of fabricating DCBs, a novel kind of DCB named aminoesterenamide is presented via three‐component reaction. The aminoesterenamide‐containing CANs exhibit easily tailored structures and properties besides reprocessability.