It is a challenge that extracting rubidium directly from the salt lakes by electrochemical method, because of the low content of rubidium ions and other complex co-existing ions in the salt lakes. Copper hexacyanoferrate (CuHCF) with good electrochemical performance in desalination and aqueous batteries, may be used as the electrode material of electrochemical extracting rubidium. In this paper, CuHCF is synthesized by one-step precipitation method by adding copper ions in K3Fe(CN)6 solution. Cyclic voltammetry is studied with the CuHCF electrode sheets in alkali metal ions and simulated brine electrolytes. The alkali metal ions insertion and de-insertion in the electrodes are mainly controlled by diffusion process with cyclic stability. The diffusion rate of K+ is the largest, Li+ the smallest. The insertion and de-insertion process are reversible in Na+, K+ and Rb+ ionic solutions. The cyclic voltammetry current of the CuHCF electrode sheet in Na+ ionic solution shows two pairs of redox peaks. The cyclic voltammetry currents of CuHCF electrode sheet in simulated brine mainly show is the peak current of that in Na+ and K+ ionic solutions.