As to the low efficiency and low degree of sphericility with frequently impeded in atomizing process of traditional gas-atomizing nozzle, a new nozzle with laval outlet accompanied by ventilation hole and guiding pipe is designed to prepare spherical alloy powders for laser cladding. The gas velocity at the outlet of nozzle is simulated and measured by pitot tube total pressure method, and the air pressure on the nozzle centerline is tested by U-shaped water pressure gauge. After the atomization experiments, the powder achieved is analyzed by scanning electron microscoope (SEM) and Hall flowmeter. The results show that compared with the traditional nozzle, the innovative nozzle can produce supersonic flow at the outlet, the process of atomization is unimpeded, and the efficiency of atomization is improved significantly. With excellent characteristics of good liquidity and granularity distribution, the spherical powder can meet the requirement of laser cladding.