A treatment method of waste fabric containing polyester fiber and elastic fiber is provided. The method includes the steps of using at least one polar solvent to perform at least a two-stage separation treatment on the waste fabric and recycling the waste fabric after the treatment. The at least one polar solvent is selected from the group consisting of dimethylformamide (DMF), dimethylacetamide (DMAC), N-methylpyrrolidone (NMP), gamma-butyrolactone (GBL), and dimethylsulfoxide (DMSO).