Electrochemical energy storage and conversion technologies are crucial in the transition to sustainable energy.Renewable en-ergy-driven electrocatalytic CO2 reduction(ECO2RR)offers a promising method to convert CO2 into high-value fuels and chemical feed-stocks,which is vital for achieving"dual carbon"goals.In the ECO2RR system,copper(Cu)-based materials are widely used due to their abundance,cost-effectiveness,and unique electronic structure and adsorption properties.However,there are still challenges in this field,such as unstable valence states and structures,leading to reduced selectivity,deactivation,and poor stability.These issues hinder their transition from laboratory to industrial applications.This review firstly introduces the mechanism of ECO2RR using Cu-based catalysts,and then systematically summarizes the deactivation mechanism of the catalysts,including changes in valence states,surface poisoning,and catalyst reconstruction,along with corresponding optimization strategies.Finally,future research directions and development trends for Cu-based catalysts in practical applications is discussed.