Donor–acceptor crosslinked poly[poly(ethylene glycol) methyl ether‐methacrylate]‐block‐poly[1,1′‐bis(2‐ethylpentyl)‐6‐methyl‐6′‐(5‐methyl‐3‐vinylthiophen‐2‐yl)‐[3,3′‐biindoline]‐2,2′‐dione] (poly(PEGMA)m‐b‐poly(VTIID)n) nanoparticles with various vinylthiophene donor/isoindigo acceptor ratios are synthesized successfully. The prepared nanoparticles have uniform sizes and well‐defined core–shell nanostructures. The intramolecular charge transfer is effectively enhanced due to the incorporation of acceptor groups after the crosslinking reaction. A transistor memory device is assembled using the synthesized polymer and has nonvolatile flash‐type memory and amphiphilic trapping behavior. The optimized devices exhibit a significant memory window of approximately 38 V, a retention ability of over 104 s, and an endurance of at least 100 cycles. This study examines multiple applications of crosslinked core–shell nanoparticles, which demonstrates their promise as charge‐storage dielectric materials for use in organic memory devices.