The production of a large number of mobile devices has made more and more people pay their attention to the development of mobile software. By developing various kinds of mobile terminal software, they can effectively meet people's needs in life,learning and production, which have greatly promoted the social and economic growth. This paper discusses on the application advantages of Java in mobile terminal software development, analyzes the impact of Java on mobile terminal software architecture,and takes the development of mobile terminal encryption software as an example to explore the development process of mobile terminal software based on Java.