Heteroatom-doped carbon materials have drawn enormous attention as high-performance electrode materials owing to their widely tunable surface properties and structures, yet their facile obtainments have been mostly hindered by complex synthesis routes and low heteroatom-doping efficiency. Herein, we showcase the simple synthesis of N, P co-doped carbon nanomaterials (NP-C) with beneficial pore hierarchy applying the dehalogenation of polyvinyl dichloride (PVDC) by KOH at room temperature and high-efficiency functionalization of remained carbon skeleton using melamine and NaH2PO2. The concentration and configuration of N and P heterodopants can be simply tuned by altering the calcination temperatures. The resulted material prepared at 700 °C delivers superior capacitive performance: a high specific capacitance (Cs) of 367.5 F g-1 at 0.5 A g-1 and a capacity retention of ~95% after 10000 cycles at 10 A g-1. As analyzed by Dunn method, ~27.8% of complete capacitance is contributed by pseudocapacitive charge storage, which thanks to the high-content N (~6.3 at.%) and P (1.3 at.%) doping. Our facile preparation method can be potentially extended to the synthesis of more binary and ternary heteroatom-doped carbon nanomaterials for broad electrochemical applications.