The invention relates to a device capable of achieving heating, disinfection and PM2.5 reduction through off-peak electricity energy storage. The device comprises an equipment shell, a first-level fan, a pressure equalizing chamber, a second-level fan, an air distribution channel, a left ascent channel, a right ascent channel, a left descent preheating chamber, a right descent preheating chamber, a left ascent preheating chamber, a right ascent preheating chamber, an electric heating chamber, an electric heating body, a descent heat storage chamber, an acid refractory heat storage body, an alkaline refractory heat storage body, a long heat-resistant steel bar, a short heat-resistant steel bar, an ascent heat storage chamber, a phase-change heat storage body, a front normal-temperature air channel, a rear normal-temperature air channel, a warm air spray-out guide plate, an intelligent control power supply box, various heat-resistant steel partitions and the like. According to the device, unique two or more three-chamber combined modules are adopted, all-day heating can be achieved by the adoption of off-peak electricity, the functions of high-temperature combustion, high-temperature adsorption and chemical combination, transverse heat transfer and waste heat recovery are achieved, indoor air can be thoroughly purified at no cost, no secondary population is generated, the maintenance is avoided, the accidents of the burn injury, scald injury, burnout of furniture, fires, electric shock and the like can be avoided as well, and the device is suitable for indoor energy storage heating and air purification in winter.