Graphene, as the prominent example of two-dimensional (2D) Dirac semimetals, has attracted tremendous attention. However, Dirac points in 2D systems including graphene are greatly influenced by spin-orbit coupling (SOC), and easily open gaps. Besides, although several layer groups (LGs) with SOC Dirac points have been reported, a large number of LGs and actual materials are still missing. Here, based on symmetry analysis, the first-principles calculation, and the high-throughput search, we find that 27 of the 80 nonmagnetic LGs contain spin-orbit Dirac points (SODPs), and screen 65 actual materials from the huge 2D inorganic crystal database (6351). Based on symmetry analysis, SODPs can be classified into two categories: centrosymmetric and non-centrosymmetric systems. In addition, we also discover that the highest order of the SODP is linear, which can be read off from their effective model. Under breaking the symmetries, a Dirac point can be transformed into a pair of Weyl points with opposite chirality. Our work not only provides theoretical guidance for the study of Dirac points in 2D systems, but also provides a large number of concrete candidate materials.

石墨烯作为二维（2D）狄拉克半金属的突出例子，引起了极大的关注。然而，包括石墨烯在内的二维系统中的狄拉克点受自旋轨道耦合（SOC）的影响很大，并且很容易打开间隙。此外，虽然已经报道了几个具有 SOC 狄拉克点的层组（LG），但仍然缺少大量的 LG 和实际材料。在这里，基于对称性分析、第一性原理计算和高通量搜索，我们发现 80 个非磁性 LG 中有 27 个包含自旋轨道狄拉克点 (SODP)，并从巨大的二维无机晶体中筛选出 65 个实际材料数据库（6351）。基于对称性分析，SODP可以分为两类：中心对称系统和非中心对称系统。此外，我们还发现 SODP 的最高阶是线性的，这可以从他们的有效模型中读出。在打破对称性的情况下，一个狄拉克点可以转化为一对具有相反手性的外尔点。我们的工作不仅为二维系统中狄拉克点的研究提供了理论指导，而且提供了大量的具体候选材料。