Cerium-based porous carbon microsphere (Ce/PCM) was synthesized by one step ultrasonic spray pyrolysis (USP), and the structure was analyzed by scanning electron microscopy (SEM), transmission electron microscopy (TEM), Brunauer-Emmett-Teller (BET) and Raman spectrometer. Furthermore, the adsorption performance of Ce/PCM was tested by Rhodamine B. (Rh B). The characteristic’s results showed the structure and specific surface area of Ce/PCM were affected by the pyrolysis temperature, and 800-Ce/PCM had the maximum specific surface area as 472.9 m2·g−1. The adsorption evaluation showed that 800-Ce/PCM had the best removal efficiency, and the maximum adsorption capacity was as high as 508.2 mg·g−1. The results suggested the adsorption kinetics of Ce/PCM for Rh B follows pseudo second-order dynamics and Freundlich model, which indicated that the adsorption process includes chemical adsorption and multilayer adsorption. Kinetic thermodynamic studies proved the absorption was endothermic reaction. The analysis of absorption mechanism indicated that the removal mechanism mainly includes pore filling, hydrogen bonding and surface adsorption.