Coal-derived hard carbons (CHCs) have considerable potential as sodium storage materials because of their abundant resources and structural diversity. Nevertheless, the smaller layer spacing and ordered carbon microstructure of CHCs bring about low charge/discharge rates and poor cycle life of sodium-ion batteries (SIBs), rendering it challenging to support large-scale energy storage applications. Herein, the preoxidation strategy is employed to achieve multiscale structure optimization of CHCs and improve its sodium storage capacity. The oxygen content in preoxidized coal reached 15.2%, contributing to increasing the cross-linked structure of the coal materials. Particularly, insertion of Na