With the rapid development of technology, the application area of embedded systems continues to broaden. This makes the development of embedded systems facing increased pressure of quality, cost and cycle time. On the other hand, agile methods have been more and more adopted in traditional software projects. Many studies indicated that agile methods have significant values to adapt to changing requirements, increasing the productivity and the quality of the final product. Therefore, the application of agile methods in embedded systems development naturally has drawn attentions from researchers and practitioners. This paper applies systematic reviews to systematically understand the application status of agile methods in embedded system development. Through reviewing and analyzing 49 literatures since Agile Manifesto has been announced, this study tries to answer the following three questions: 1) In different types of embedded systems development, what is the overall application status of agile methods; 2) What characteristics of embedded systems are suitable to apply agile methods; 3) How to improve current agile methods (practices) to better adapt to the development of embedded systems. The study shows that, although there are some differences in the degree of application, agile methods have been applied in the development of different types of embedded system developments. However, the traditional agile methods also need to be appropriately revised to adapt to the characteristics of different types of embedded development projects.