The atomization model about interaction of cavitation, turbulence and aerodynamics is put forward through the analysis about the control equation of jet disturbance, the computed result of the dispersive jet equation, according to the conceptual model of spray based on two-phase flow. The action of cavitation and turbulence formed inside nozzle are thought to lead to the first atomization near the nozzle exit, while the aerodynamic effect controls the following second atomization process. And the critical Weber number 〖BP(〗［We］=12(1+1.077Oh1.5)〖BP)〗 is taken as the judgment index for occurring of the second atomization or not. The critical velocity for liquid splitting into droplets is 60 m/s according to the analysis of break mode about liquid drop, furthermore, jet fragmentation and film fragmentation occurs in the first and second atomization respectively. The typical mechanism of dust capture by water-cloud is improved through the active collision theory of droplet to dust particle. It is considered that an optimal relationship exists between collection rate and droplet size when gas containing dust is unsaturated and its temperature is higher than that of liquid, moreover, low fluid velocity can be propitious to the collection of tenuous droplet to exiguous dust on the basis of the same liquid-gas ratio and the same quantity of droplets.