The singlet oxygen generator (SOG) is the heart of chemical oxygen iodine laser. A new swirl-jet-type SOG was proposed which consists of a reaction part and a separation part. Planar laser-induced fluorescence combined with maximum entropy method were used to study the droplet size distribution, and a modified Muschelknautz model and Computational Fluid Dynamics were used to simulate the separation efficiency of vapor and liquid phases. The results of the net reaction predict 99.2% conversion of chlorine and 42.2% yield of singlet oxygen, demonstrating the superiority of the new type of SOG.