Provided is a method of treating wastewater and recovering resources in acrylic fiber production, comprising the following steps: 1) filtering wastewater from water-washing and filtering unit of acrylic fiber plants by a filter to intercept and recover high-molecular-weight polymer contained therein, and then making the recovered polymer returned back to the acrylic fiber production and entered the finished product, optionally, reusing part of filtered wastewater as low salinity water in the water-washing and filtering unit: 2) removing non-interceptable high-molecular-weight polymer in the wastewater by subjecting the wastewater to coagulation and air floatation treatment; 3) introducing the effluent into biological treatment unit and adding polyvalent metal ions as an adsorption promoter to increase the removal of the non-biodegradable organics in the biological treatment unit; and 4) removing the organics remained in the effluent from the biological treatment unit by an advanced treatment.