Heteroatom doping and well-tuned porosity are regarded as two important factors of porous carbon materials (PCMs) for various applications. However, it is still difficult to tune a single variable while retaining the other factors unchanged, which restricts rational and systematic research on PCMs. In this work, in situ nitrogen-doped porous carbon material (NPCM-1) and its non-doped analogue PCM-1 were prepared by direct pyrolysis of conjugated microporous polymer precursors (TCMP-1 and CMP-1 respectively) with the same skeleton structure. It was found that the CO2 adsorption capability of the PCMs was significantly enhanced compared with their CMP precursors thanks to the optimized pore configuration. Meanwhile, NPCM-1 exhibits much better performance in supercapacitive energy storage than PCM-1 even though these two PCMs possess comparable porosity properties, which is probably due to the much improved electrical conductivity and wettability with the electrolytes because of the introduction of nitrogen doping. Thus, this work provides a valuable insight into the design and preparation of high performance PCMs for CO2 capture and energy storage applications.