With the rapid development of 3D rendering technology, the country attaches great importance to the strategic significance of the "digital city", and the emergence of high-performance mobile devices has given the mobile terminal 3D city visualization technology a broad development prospect and strong technical support. Based on the Android mobile platform, this paper studies the key technologies of 3D city visualization. Focus on the establishment of 3D city models, 3D data organization, and the use of their respective advantages in 2D and 3D to realize the linkage display of 2D and 3D city scenes, and realize the multi-resolution display of 3D cities through the streamlining of building models and the study of model selection strategies. The final design realizes the mobile terminal 3D city visualization interactive system.