Flexible electronic technology has developed rapidly in recent years, and more and more flexible electronic systems require flexible, high-performance integrated circuits to achieve data processing and communication. High performance flexible integrated circuits can be obtained by thinning silicon chips, but the performance of silicon chips may change after thinning, and defects or breakage are easy to occur in the process of preparation, transfer and packaging, resulting in chip performance degradation or even failure. Therefore, the preparation process and flexible packaging technology of ultra-thin chips are very critical to the preparation of high reliability flexible chips. In this context, this paper reviews the research progress of mechanical and electrical properties of flexible silicon chips, introduces the thinning process and flexible packaging frontier technology of several ultra-thin silicon chips, and summarizes and prospects the application and development of ultra-thin silicon chips in the field of flexible electronics, so as to provide reference for further research on flexible silicon-based chip technology.