The unsymmetric dimethyl hydrazine (UDMH) wastewater was degraded by the microwave (MW) enhanced Fenton, and the effect factors, such as MW power, dosage of H₂O₂, pH, Fe²⁺:H₂O₂ molar ratio on wastewater treatment were studied. The best degradation conditions were determined by the orthogonal experiment. Results show that, the chemical oxygen demand(COD) removal rate could be 98.4% on condition that MW power is 280 W, H₂O₂ (68.5 g·L^-1) dosage 4.0 mL, pH 4.0, Fe²⁺:H₂O₂ molar ratio 1:16 and reaction time 8.0 min.