Porous carbon materials have been widely used for CO2 adsorption, but their preparation was subject to conditions such as raw material cost, activator corrosion, and temperature. In this study, nitrogen-doped porous carbonaceous adsorbents were prepared in a low temperature region (400-550 degrees C) by one-step composite nitrogen doping method, using low-cost oil residue as raw materials and less corrosive NaNH2 as activator. The CO2 adsorption performances of the prepared N-doped porous adsorbents were systematically explored. The results showed that optimal oil residue-derived carbonaceous adsorbent owned excellent amount of CO2 adsorption up to 3.51 and 5.63 mmol/g at 298 and 273 K under 1 bar, respectively. It was discovered that the congenerous influences of porous structure, nitrogen content and V-n of the adsorbent affected their CO2 adsorption performances under 1 bar. Importantly, these oil residue porous carbonaceous adsorbent also was verified owning fine selectivity of the CO2 over N-2 (15.7), which attributed to its high V-n and nitrogen content. Furthermore, optimal sample OAC-500-2.5 owned medium Q(st) (21-26 kJ/mol), which was beneficial practical application. This work may inspire new sparks on novel nitrogen-doped adsorbent with inexpensive precursor, low activation temperature and simple preparative tactic, indicating that the nitrogen-doped sample is promising in the practical situation of CO2 adsorption.