Solar photovoltaic system maybe underperformanned because of too much dust, dirt and bird droppings, etc. 3D mapping for the cleaning robot still remains challenging in this large scale scenario. This paper presents a robust mapping system with Kinect V2 for automated photovoltaic cleaning system. Firstly, Kinect V2 is well-calibrated for a remedy to the production variety and the approach is fast and accurate. Secondly, robost mapping algorithm is proposed with the consideration of vibration, occlusion and loop closure. Gloally consistent 3D map will be built after online loop detection. And lastly, 3D pointcloud will be transformed into octree-based data structure. The data is easy to save, reload and more suitable for motion planning problem. Extensive experimental results show that the system is robust with enough accuracy for automated motion planning and navigation.