The invention provides a continuous type full-automatic chemical feeding device. The continuous type full-automatic chemical feeding device comprises a dry powder feeding system, a dehumidification and drying system, a dry powder pre-mixing system, a water supplying system, a combined groove body, a stirring system and an automatic control system, wherein the dry powder feeding system comprises a dry powder feeding machine; the bottom of the dry powder feeding machine is connected with the dehumidification and drying system; the dehumidification and drying system comprises a spiral rod and a spiral sheet; the spiral rod is connected with a motor I; the spiral rod is of a hollow structure; a silica gel heating sheet is arranged on an inner wall of the spiral rod; the spiral sheet is provided with rectangular grooves and arc-shaped grooves; each rectangular groove is internally provided with a PTC (Positive Temperature Coefficient) heating sheet. The continuous type full-automatic chemical feeding device is provided with the dehumidification and drying system, the effects of preventing powder from being condensed, heating and keeping heat are realized and a condition that chemical powder is affected with damp and caked or goes bad is avoided; a chemical dissolving tank is provided with a material level instrument and a storage groove is internally provided with a liquid level meter, and metering of chemical liquid in the whole chemical feeding device is monitored at any time; the chemical feeding device is automatically started and stopped through a controller, so that the device is continuously operated and automation is realized; the operation difficulty and the labor cost are reduced.