We demonstrate a novel and very efficient interfacial polymerization method for the synthesis of high-quality polyaniline-wrapped carbon nanotubes (CNT–PANI), which represent a novel type of CNT–polymer heterostructure. The interfacial polymerization at the liquid–liquid interface is prone to form uniform core–shell CNT–PANI composites due to the presence of π–π interactions between PANI and CNT walls. Then electrocatalytically active platinum nanoparticles (Pt NPs) were loaded on the carbon nanotubes (CNT) through the introduction of electron-conducting PANI to bridge the Pt NPs and CNT walls with the presence of platinum–nitride (Pt–N) bonding and π–π bonding. The Pt NPs with controllable loading density were uniformly dispersed onto the CNT–PANI walls. The Pt/CNT–PANI hybrids possess exceptional electrochemical activity and exhibit excellent electrochemical stability towards methanol oxidation and oxygen reduction.