针对凸多面体组合结构提出了一种浮态计算新方法。首先对浮体进行四面体网格剖分，然后利用二重迭代法计算水面方程。二重迭代法包含内、外两层迭代，分别模拟浮体的升沉和旋转运动。针对某半潜式海洋平台，展开了浮态模型实验。文中将提出的算法与著名计算机辅助船舶设计和制造软件 Maxsurf 进行了对比测试。实验和对比测试结果表明: 该方法具有清晰的物理意义，算法精确可靠、收敛性好，比传统方法更适合分析 “凸多面体”组合结构的浮态问题。

A new method for calculating the afloat condition of convex polyhedron composite structure was pro-posed． Firstly，the afloat object was meshed by the tetrahedra，and then the water plane equation was calculated by the double iterative method，which consists of the inner and outer iterative procedures simulating the heaving and rotation motions of the afloat object respectively． The afloat condition experiment was carried out for a semi-submersible offshore platform． The algorithm proposed in this paper was also compared with Maxsurf which is the famous computer aided ship design and construction software． The experimental and comparative test results show that the method has clear physical meaning，the corresponding algorithm is accurate and reliable with good conver-gence． This new method is more suitable for analyzing the afloat condition of the convex polyhedron composite structure than the traditional method．