The Hybrid App combines the advantages of Native development and Web development, which takes more and more proportions in the mobile application development and desktop application development. This paper realizes bidirectional communication mechanism between WebView and Native, set up development framework for Hybrid App, and optimizes the performance of Hybrid App by means of off-line storage for Web data and delta update based on byte stream for Web files. Finally, the development framework and optimization mechanism are actually tested and the collected data are analyzed, and the experimental results reveal that development framework and optimization mechanism have good feasibility and practicability.