为了实现复杂生物危害现场病原体的快速侦检，需要制备多样化的生物样品，建立多模态生物光谱数据库，最终实现有针对性的危害病原体快速灭活。其中，雾化喷嘴的设计是制备高质量生物样品的关键技术。该技术可以将液体生物样品雾化成细小雾滴，再通过低温冷冻+升华作用形成生物样品颗粒。通过空气辅助雾化喷嘴的优化设计，可以在不损害生物活性的低流量、低压力条件下，获得微小且均匀的雾化液滴。文中采用RANS+DDM方法对喷雾场进行模拟，对空气辅助雾化喷嘴在常温和低温加热条件下的雾化特性进行了分析模拟。同时，采用LES+VOF方法对近喷孔区域气体旋流对液体射流的扰流作用进行了模拟，分析了射流的雾化机理。最后，使用空气动力学粒度仪对空气辅助雾化喷嘴的雾化效果进行了测试，结果证明：喷嘴的雾化效果良好，可实现平均粒子直径约1μm的超细雾化；通过低温喷雾冷冻干燥制备的生物样品质量达到了设计要求，可以有效地实现大批量生物气溶胶样品的制备，提升生物危害现场病原体的侦检及防御能力。

In order to realize the rapid on-site detection for pathogens in complex biological hazards，it is necessary to prepare a variety of biological samples，establish a multimodal biospectral database，and eventually achieve targeted rapid inactivation of pathogens.Ultrafine atomizer design is a key technology to prepare high-quality biological samples.The technology can atomize liquid biological samples into small droplets，and then the bioaerosol particles can be formed after low-temperature freezing and sublimation drying.Through the optimal design of the air-assisted atomizer，the ultrafine and uniform atomization can be obtained under the conditions of low flowrate and low pressure without damaging the biological activity.In this paper，the spray process was simulated by means of RANS+DDM method，and the atomization characteristics of the air-assisted atomizer were analyzed at normal temperature and low temperature with heating power.At the same time，LES+VOF method was also adopted to test the turbulence effect of gas swirling near the nozzle on the liquid fluidics，and the atomization mechanism was analyzed.Moreover，the atomizing effect of the air-assisted atomizer was tested by an aerodynamic particle size tester.The results show that the air-assisted atomizer has good atomizing effect and can realize ultrafine atomization of particles with a diameter of around 1μm.The quality of biological samples prepared by spray-freeze-drying method can meet the design requirements，so it can effectively prepare bioaerosol samples in mass quantities and improve the detection and defense capability for pathogens on the site of biological hazards.