An environment-friendly drying and dedusting device for persulfate comprises a cyclone separator connected with a dryer. A top outlet end of the cyclone separator is communicated with an inlet end of a dedusting chamber through a pipe. An outlet end of the dedusting chamber is connected with an inlet end of an environment-friendly dedusting box through a pipe. A water tank is disposed at the bottom of the environment-friendly dedusting box. A sprinkler and an exhaust pipe are arranged at the top of the environment-friendly dedusting box. The sprinkler is connected with a water outlet of a sprinkling water pump, and a water inlet of the sprinkling water pump is connected with the water tank. A water outlet pipe is connected to the bottom of the water tank, and a water inlet pipe is disposed at the top of the water tank. Material recovery, efficiency and environmental friendliness can be achieved by cyclone separation, sedimentation by the dedusting chamber, absorption by the environment-friendly water tank and the like, and the environment-friendly drying and dedusting device for persulfate has high practical value.