To improve the thermal decomposition performance of ammonium perchlorate （AP）， Cu₁/Al₂O₃ single-atom catalyst was prepared through the evaporation induced self-assembly （EISA） method. The morphology and structure of prepared Cu₁/Al₂O₃ single-atom catalyst were characterized by X-ray diffractometer （XRD）， inductively coupled plasma （ICP-OES）， transmission electron microscopy （TEM）， X-ray absorption spectroscopy （XAS） and X-ray photoelectron spectrometer （XPS）. The effect on the thermal decomposition of ammonium perchlorate（AP）was also investigated by differential scanning calorimetry （DSC） and thermal gravimetry （TG）. Results show that Cu atoms were dispersed and stabilized through oxygen bridge bonds on the Al₂O₃ supporter. The Cu loading was determined to be 8.7%. When the content of Cu₁/Al₂O₃ single-atom catalyst is 5%， the high-temperature exothermic decomposition peak temperature of AP decreases to 319 ℃， which was 85 ℃ lower than that of pure AP. This Cu₁/Al₂O₃ single-atom catalyst exhibits superior catalytic performance on the thermal decomposition of AP， which was more effective than Cu（NO₃）₂·3H₂O and nano-CuO catalyst.