Embedded system is becoming a hot issue for a lot of appliances. However, the development of embedded systems faces the challenge of high risks from market pressures and lack of domain expertise. In this paper, we introduce a risk-driven model for embedded system developing. Driven by risk evaluation, the model guides the embedded system developing in a module-based approach. More- over, a risk evaluation framework composing of three-dimension metrics is provided with the model to address and track the development risk, including metrics for economy, personnel and technology. A case study is provide d to demonstrate how the model and framework are applied.