Ordered mesoporous carbon materials with diverse architectures including flakes, fibers, rods, gyroids, gyroids with nanoparticles, and spheres were successfully prepared from liquefied wood by controlling the nucleation and growth process through modulating the concentration of HCl via a facile hydrothermal/soft templating method. Display omitted •Well-defined gyroid-like ordered mesoporous carbon materials were synthesized through a facile hydrothermal/soft templating method.•Biomass derived liquefied wood was used as the carbon precursor.•The morphology of ordered mesoporous carbon materials can be readily designed via the nucleation and growth process by changing the concentration of HCl. A HCl concentration-controlled hydrothermal/soft-templating strategy is proposed to prepare ordered mesoporous carbons (OMCs) with diverse morphologies from flakes to gyroids then to spheres by using liquefied wood as a carbon precursor. The effect of nucleation and growth process on morphology change was systematically studied. Results showed that an accelerated nucleation rate and a transformation of self-assembly pattern from slow and weak aggregates to fast and strong assembly are achieved in accordance with increasing HCl concentration. Detailed mechanism studies reveal that a reaction solution without seed nuclei formed at the initial stage of the hydrothermal process under low HCl concentration will lead the micelles to slowly self-assemble into microscale flakes, whereas a high HCl concentration will make the micelles rapidly self-assemble into rodlike micelles and further grow along the surface of the initially formed seed nuclei to produce nanoscale products with an annular structure. The OMCs with highly ordered p6mm mesostructure synthesized at a proper HCl concentration of 1.61 M exhibit higher electrochemical performance than the less ordered OMCs. The detailed study of nucleation and growth mechanism provides new understanding of controllable design and synthesis of OMCs with desired morphology.