As an important component of urban landscape elements, garden plants have the role of improving urban ecological environment and forming landscape effects. Digital landscape is a high-simulation model of the system combined with computer hardware and software systems, which allow analysis of the application of computer simulation in the analysis of the value of urban landscape design. In this paper, we propose a “Task-Crowd-Process-Evaluation” computer simulation analysis framework to support management decision, which can form 2D or 3D spatial data, realize real-time and statistical analysis, make use of the multidimensional, efficient, and humanized human living environment, and make the environment landscape planning more reasonable and practical. The simulation shows that the effective use of urban vegetation can not only beautify the urban landscape, but also play the function of rainwater utilization.