本文给出了均质长方体模型重力梯度各分量的理论表达式。通过地球各圈层的密度差异,从GOCE观测数据中分离出地壳的重力梯度信息。利用均质长方体模型建立地壳重力梯度与其厚度的物理方程,通过粒子群优化算法反演青藏高原地壳厚度。反演结果显示,青藏高原地壳平均厚度约为52.29km,中部地区地壳平均厚度达70km。与已有地壳厚度研究成果对比分析表明——本文提出的反演研究地壳厚度的方法是切实可行的。 In this paper, the theoretical expressions of the components of the gravity gradient of a homogeneous cuboid model are given. The crustal gravity gradient information is separated from GOCE observations by the density differences of all the earth’s rings. The physical equations of crustal gravity gradient and its thickness are established by homogeneous cuboid model, and the crustal thickness of the Qinghai-Tibet Plateau is retrieved by particle swarm optimization algorithm. Inversion results show that the average crustal thickness of the Qinghai-Tibet Plateau is about 52.29km and the crustal average thickness in the central region is up to 70km. Compared with the existing research results of crustal thickness, it is shown that the method proposed in this paper to study crustal thickness is practicable.