The wet oxidation process is a key technology for fabricating a vertical cavity surface emitting laser (VCSEL), but the stability and controllability of the oxidation process require further improvement. Herein, the oxidation temperature, which is the core factor in the oxidation process, was studied in depth. By establishing a control experiment, the effect of the oxidation temperature on oxidation rate and shape of the oxidation pore was explored. Understanding this effect is vital to accurately control the size and shape of the oxidation pore and improve the electro-optical characteristics of the device. Moreover, the oxidation temperature control curve was simultaneously optimized based on the oxidation reaction mechanism of AlGaAs. Experimental results indicate that samples oxidized based on the oxidation temperature control curve exhibit excellent thermal stability and high overall structural reliability.