中文摘要：

模型转换是模型驱动开发中的核心技术．为了解决复杂的转换问题，需要将多个相对简单的转换组合起来构成组合转换．目前存在多种转换技术，它们之间存在异构性，阻碍了组合转换的实现．首先分析实现组合转换的必要条件，进而提出一个组合转换模型，其中主要包括公共类型表示、公共模型表示、公共转换描述和组合转换定义语言等部分，用以实现支持多种转换技术的组合．另外，还介绍了一个组合转换平台的设计与实现，并通过一个案例说明所提方法及工具的可行性．

英文摘要：

Model transformation is the key technique of model driven development. To handle difficult problems, it is necessary to combine smaller transformations into a complex one. Due to the heterogeneity among different transformation techniques, it is difficult to combine them together. The paper analyzes four essential conditions for composite transformations. Next, the paper proposes a composite transformation model, which consists of common type representation, common model representation, common transformation description, and composite transformation definition, in order to realize composite transformations. The paper also introduces the design and implementation of a transformation composition framework. A case study is also presented to illustrate the feasibility of this approach.