Mobile application security detection and protection is an active research topic in the domain of software security. The traditional security solution is to install the APP developed by security vendors on user terminals. However, for the normal users lacking of security awareness, they do not understand the seriousness of security threat and the importance of security management, thus leading to insufficient terminal security defense. It is necessary to take protection from the threat source and transmission route. This paper implements various security measures including source code authorship attribution based on coding style, mobile application security reinforcement and channel monitoring, and mobile application security detection based on deep learning over the view of threat source, transmission route and threatened terminal. A mobile application security ecological chain is also constructed to protect users' personal information security. The paper verifies the effectiveness of proposed method in the practical application environment. The results show that it can achieve the goal of all-around application security protection. Future work in this research area is also discussed.