The invention discloses a damp-proof mildew-proof wall used for a building. The wall comprises a wall basic body, a negative ion coating, an inner wall wallboard and an air layer A are sequentially arranged from outside to inside on the right side of the wall basic body, a heat-preservation layer, an anti-crack adhering layer, a damp-proof layer, an air layer B and a veneer are arranged from inside to outside on the left side of the wall basic body, the upper side and the lower side of the air layer are connected with a circulating pipeline, the part, on the lower side of the air layer, of thecirculating pipe is provided with a temperature gauge used for measuring gas temperature in the circulating pipeline, a heater is further arranged on the circulating pipeline and used for heating gasin the circulating pipeline, the heater is further connected with an air inlet pipe which is communicated with the circulating pipeline, the air inlet pipeline is provided with an air pump A, the part, on the upper side of the air layer, of the circulating pipe is provided with an air pump B, and a pressure gauge is arranged on the circulating pipeline and used for measuring pressure in the circulating pipe. The wall can realize dehumidification and mildew prevention and can be protected, and meanwhile indoor air can be purified.