Abstract Polyvinyl chloride (PVC) is the world's third‐most widely produced plastic polymer. Directly transforming PVC to carbonaceous materials for CO 2 capture provides an environmentally friendly and attractive strategy to recycle plastics. In this work, a simple and effective method was developed to prepare PVC‐derived carbon spheres. In this method, the classical “spheroidization” process shaped the original PVC powders into millimeter spheres, and a special dehalogenation and cross‐linking process in the presence of a phase‐transfer catalyst transferred the thermoplasticity of the PVC‐spheres into thermosetting, which stabilized the shape. Furthermore, by rationally adjusting the activation conditions, the porous structure of the carbon spheres was well optimized. With a specific surface area up to 1738 m 2 g −1 and the developed microporous structure, the as‐prepared carbon spheres showed not only excellent performance in pure CO 2 adsorption (8.93 mmol g −1 , 39.3 wt% at 0 °C and 5.47 mmol g −1 , 24.1 wt% at 25 °C), but also outstanding adsorption capacity and recyclability in low‐concentration CO 2 capture, even superior to conventional molecular sieves.