激光粉末床熔融（LPBF）技术具有成形精度高、表面粗糙度低、成形件性能优异等特点，是目前金属增材制造领域中应用最广泛的一种成形技术。其中，铺粉过程作为LPBF技术的关键环节，粉末床铺粉质量对铺粉致密度及成形件性能具有重要影响，基于此，本文综述了LPBF技术中铺粉致密度的影响因素。首先，总结了粉末床铺粉质量的表征评价方法，如图像分析法、X射线原位监测法和取样器法等。在此基础上，从粉末特征和铺粉工艺出发，分别阐述了粉末粒度、粉末形貌、粉末制备方法、粉末再循环及铺粉工艺参数对粉末床铺粉致密度的影响规律。其中，粉末的粒度分布和形貌是影响铺粉致密度关键因素，较宽的单峰分布和粗细颗粒混合的双峰分布有利于提高粉末堆积密度。粉末的形貌越接近球形，粉末流动性越好，越有利于提升粉末铺展性和铺粉均匀性。粉末堆积密度和铺粉均匀性共同作用将提升粉末床铺粉致密度和成形样品的致密度。铺粉工艺条件的变化可以影响粉末床的铺粉质量及密度，其中控制合理的铺粉速度、选用滚筒类型的刮刀和增大基体的粗糙度将进一步提升粉末床的铺粉致密度。最后，本文对进一步提升粉床的铺粉致密度的方法和技术进行了展望。

Laser powder bed fusion (LPBF) technology is one of the most widely used forming technologies in the field of metal additive manufacturing because of its high forming accuracy, low surface roughness, and excellent performance of the formed parts. In this paper, we review the factors influencing powder packing density in LPBF technology, which is a key part of LPBF technology. First, the methods of powder bed quality characterization and evaluation, such as image analysis, X-ray in-situ monitoring, and sampling method, are summarized. On this basis, the influence of powder particle size, powder morphology, powder preparation method, powder recycling, and powder recoating process parameters on the powder bed packing density is described from powder characteristics and powder recoating process, respectively. Among them, the particle size distribution and morphology of the powder are the key factors affecting the powder packing density, and the wider single-peak distribution and the bimodal distribution of coarse and fine particles are favorable to improve the powder packing density; the closer the powder morphology is to spherical shape, the better the powder flowability is, which is favorable to improve the powder spreading homogeneity. The powder packing density and spreading homogeneity together will improve the powder bed packing density and the density of formed samples. The change of powder recoating process conditions can influence the powder spreading quality and packing density, among which controlling reasonable recoating speed, choosing roller type scraper, and increasing the roughness of substrate will further improve the powder bed packing density. Finally, this paper presents the prospect of methods and techniques to further improve the powder bed density.