Potassium which is abundant in the Earth’s crust and has similar physicochemical properties to lithium, has broad development prospects in the field of ion batteries. However, compared with lithium ion, the potassium-ion radius is relatively larger, leading to the lower migration rate of potassium ion in the material and the material is subjected to larger structural stress. This causes insufficient electrochemical performance advantages of the Potassium-ion battery. Therefore, developing cathode and anode material with stable structure and the capability for reversible reaction, and electrolyte which matches well with material has become a hot topic in the research of Potassium-ion battery. In this review, the latest research progress about cathode material, anode material and electrolyte of Potassium-ion battery at home and abroad are introduced, and we also prospect the future development tendency of Potassium-ion battery.