With the increase of daily file processing capacity of Android mobile phone users, on the one hand, it will affect the performance of mobile phone operating system, on the other hand, it will bring unnecessary trouble to Android mobile phone users. Moreover, the Android mobile phone operating system itself does not provide file management software, which affects the experience of Android mobile phone users to some extent. In this paper, according to the operability of Android mobile phone terminal equipment and the customization of software, a file management system based on Android is designed and implemented, which can effectively help Android mobile phone users to handle daily files and manage file operations stored on local mobile phones. This paper aims at the design of Android file manager. Firstly, the background of Android file manager is briefly introduced, including the current situation and future development trend of Android smartphone operating system, research content and significance, system performance and demand analysis. Secondly, according to the development platform of Android, the construction method of this system development environment is given, and it is downloaded and packaged on the target mobile phone Samsung i9000 for real machine testing. This paper introduces the overall design mode of Android file manager system, analyzes the functions of each sub-item of the interface design mode of Android file manager, further expands the characteristic functions of Android file manager, and completes the detailed design in combination with the market demand of Android mobile phone users. In addition, this paper also tested the mainstream Android mobile phone operating system on the real machine, and determined the platform version suitable for Android system development. Then it introduces the analysis of key technologies used in the development process of Java, XML and database. According to the demand analysis of Android file manager, the functions of each sub-module are designed in detail, and then the detailed use case description is listed according to each sub-module function. Android file manager divides the system into the basic operation function of Android files, file dragging function, file searching function, file setting function, file library favorite function, APK application management function and multi-label file display function. Then it is written in Java language, with the intention and activity mechanism provided by Android as data mapping operation, reading the file information in SD card /mnt/sdcard directory and displaying the corresponding file icon format. Combined with open source software, the model design of Android file manager is completed in Eclipse IDE environment. On the basis of the above functional module design, the main interface design of Android file manager is further improved to provide a brand-new interface style for Android mobile phone users. Finally, this paper also points out the shortcomings of Android file manager, and puts forward some functional suggestions, such as adding ZIP decompression function and fixing Bug operation, in order to release it in the Android market as soon as possible and win the favor of customers. Keywords: file manager; Android file type; android