Abstract: The method of airflow ultrasonic spray thermochemical process was discussed, which can be used to produce nano-scaled amorphous WO₃-CuO composite powders directly. The hot decomposition process and the conversion process from amorphous to micro-crystal of the powders were investigated by XRD, TEM and TG-DSC. The results show that it is feasible to industrially produce nano-scaled WO₃-CuO composite powders on a large scale by means of airflow ultrasonic spray thermochemical process. The average particle size of WO₃-CuO composite powders is less than 50 nm, and their shape is spherical.