Recently, abundant resources, low-cost sodium-ion bat-teries are deemed to the new-generation battery in the field of large-scale energy storage. Nevertheless, poor active reaction dynamics, dissolution of intermediates and electrolyte matching problems are significant challenges that need to be solved. Herein, dimensional gra-dient structure of sheet–tube–dots is constructed with CoSe2@CNTs–MXene. Gradient structure is conducive to fast migration of electrons and ions with the association of ether electrolyte. For half-cell, CoSe2@CNTs–MXene exhibits high initial coulomb efficiency (81.7％) and excellent cycling performance (400 mAh g?1 cycling for 200 times in 2 A g?1). Phase transformation pathway from crystalline CoSe2–Na2Se with Co and then amorphous CoSe2 in the discharge/charge process is also explored by in situ X-ray diffraction. Density functional theory study discloses the CoSe2@CNTs–MXene in ether electrolyte system which contributes to stable sodium storage performance owing to the strong adsorption force from hierarchical structure and weak inter-action between electrolyte and electrode interface. For full cell, CoSe2@CNTs–MXene//Na3V2 (PO4)3/C full battery can also afford a competitively reversible capacity of 280 mAh g?1 over 50 cycles. Concisely, profiting from dimensional gradient structure and matched electrolyte of CoSe2@CNTs–MXene hold great application potential for stable sodium storage.