The invention discloses a high-security composite positive electrode material lithium-ion battery. According to the battery, a composite material prepared from layered small-particle size lithium cobalt oxide and lithium iron phosphate of an olivine structure is adopted as positive paste; the paste is prepared according to a certain ratio, directly coats aluminum foil and is heated and dried to prepare a positive plate; graphite is taken as negative paste, directly coats copper foil and is heated and dried to prepare a negative plate; a membrane is a composite membrane; the positive plate, themembrane and the negative plate are laminated and wound to prepare a square single battery; and the battery is packaged by using laser welding, an electrolyte is injected and the battery is charged at current which is not greater than 3A and at voltage of 2.5-4.2V. The battery disclosed by the invention has a series of advantages of being high in security performance, long in cycle life, good inrate capability, green and environment-friendly, and is suitable for the occasions with relatively high life and low temperature requirements and a relatively high maintenance cycle requirement.