As embedded software systems are widely used in many crucial areas such as automotive, energy industries and aerospace, failures of these systems will cause pollution of environment, property losses and even casualties. Therefore, safety analysis has been critical for developing these systems. The traditional safety analysis method is mainly used in the software requirement analysis stage and the design stage. However, the gap between requirement and design is a challenge in software engineering area, for it is difficult to transmit and reflect the analysis result of the requirement analysis stage into software designing. The primary reason is that the current software requirement is mainly described in natural language, in which there is ambiguity and fuzziness, and that makes it difficult to be automatically processed. To solve this problem, this paper first focuses on component embedded software and proposes a set of requirement template based on restricted natural language to reduce the ambiguity and fuzziness of natural language requirements. Then, to lessen the complexity of automated processing, requirement abstract syntax diagrams are used as the intermediate model to realize the transition between software requirement specified by restricted natural language template and AADL model, and automatically record the traceability relations between them. Finally, a tool for the method proposed above is developed based on the AADL open source system OSATE, and an example validation is carried out through the spacecraft guidance, navigation and control system GNC (guidance, navigation and control).