In the study of structure-property relationships for rational materials design, hollow multishell structures (HoMSs) have attracted tremendous attention owing to the optimal balance between mass transfer and surface exposure. Considering the shell structure can significantly affect the properties of HoMSs, in this paper, we provide a novel one-step strategy to continually regulate the shell structures of HoMSs. Through a simple phosphorization process, we can effectively modify the shell from solid to bubble-like and even duplicate the shells with a narrow spacing. Benefitting from the structure merits, the fabricated CoP HoMSs with close duplicated shells can promote gas release owing to the unbalanced Laplace pressure, while accelerating liquid transfer for enhanced capillary force. It can provide effective channels for water and gas and thus exhibits a superior electrocatalytic performance in the hydrogen and oxygen evolution reaction.