This paper presents the vision simulator which is designed for simulating vision processing and task planning for small-size humanoid, HSR-VII. Vision simulator under 3D environment is essential for developing motion planning and vision processing algorithm including foot step planning. In order to simulate gate generation and vision processing concurrently, the essential components such as walking pattern generator, vision module, visualizer and task planner are included in this simulator. Detailed program architecture is explained along with its functional descriptions. For the understanding of whole architecture, brief description of HSR-VII is introduced. To verify the effectiveness of the SW system, the simulation designed for RoboMarathon in FIRA Hurosot league is carried out using the designed simulator.