The invention discloses a small solar energy one-piece water purifier, which consists of: a filtration chamber, a pressure release valve, a water inlet pipe, a fine filter, a control chamber, a storage battery, a control regulator, a conversion device, a solar cell panel, an access opening, a water purification tank, a water outlet pipe, a polymer slow filter, an automatic blowdown valve, a full water level scale plate, a ball float valve and a slow release disinfection machine. The small solar energy one-piece water purifier provided by the invention adopts a solar energy power source to supply energy for intelligent control, is suitable for places without power, has a light structure, can be combined, is small in volume and mobile, is suitable for regions with traffic inconvenience and no road, the polymer slow filter adopts a polymer material, the raw water turbidity is less than 300 and reaches the drinking water standard, water feeding adopts an automatic pressure relief mode, and avoids the problem that most equipment cannot work normally because of too high raw water pressure, the equipment has the water purification tank in itself, thus avoiding reconstruction of a clear water pool and reducing fund input, and the equipment has water supply pressure of its own, thus overcoming the disadvantage of no water supply pressure at conventional equipment outlets.