The implementation of safety-critical systems requires multiple stages, including requirements, design, integration, verification, and testing. In recent years, model-driven development (MDD) has gradually become an important means for the design and development of safety-critical software. As no modeling language that can support the entire safety-critical system development lifecycle, we choose to integrate two widely used standard languages: system modeling language (SysML) and architecture analysis & design language of embedded real-time system (AADL). SysML and AADL provide two different views of the same system. While SysML provides a high-level system view for systems engineers, AADL establishes a low-level design view for architects, which combines hardware, opera- ting systems, and codes that realize all functions. This paper proposes an automatic transformation method from SysML to AADL. Firstly, SysML subset, called SubSysML, is defined, which mainly includes block definition diagram (BDD), internal block diagram (IBD), activity diagram (ACT) subset, and AADL Profile extended from IBD and BDD. Secondly, the transformation rules from SubSysML to AADL are defined and the transformation algorithm is designed. Then, the initial model of AADL is refined. Finally, EMF framework technology is used to implement the automatic transformation tool, and radar cases are adopted to verify the effectiveness of the proposed method.