The invention relates to a method and a device for recycling a waste salt, especially relates to a method and a device for recycling a chemical industry waste salt through a membrane process, and belongs to the technical field of the chemical industry. The method comprises the following steps: 1, dissolving the sodium chloride waste salt in pure water to form 15-30% sodium chloride waste salt water, carrying out impurity cation removal treatment on the salt water, and filtering the treated salt water by using a ceramic membrane to obtain purified salt water, wherein the salt water contains organic pollutants; 2, carrying out advanced impurity cation removal treatment on the purified salt water by using a resin to further reduce the cation content; and 3, adjusting the pH value of the obtained resin effluent, and carrying out bipolar membrane electrolysis to prepare hydrochloric acid and sodium hydroxide. The method and the device for recycling the waste salt can effectively solve the problem that the chemical industry waste salt cannot be applied and are stacked for a long time due to organic pollutants.