Abstract: A thousand-meter-scale megatall building, which consists of three equilateral-triangle arranged tear-drop towers and a central circular tower, has 10 outdoor platforms along its height with an interval of 100 m to connect the towers. The outdoor platforms are served as the emergency passageways for evacuation. As there is no shelter between two adjacent platforms, wind can pass through the building with high speed and hence cause discomfort and even danger to the pedestrians. Therefore, it is necessary to study the characteristics of the pedestrian wind environment on the platforms to guide its architectural design. Considering the limitation of blocking ratio of the wind tunnel and the requirement of sufficient measuring points on the platforms, a three-platform sectional model (abbreviated as the sub-configuration) of the megatall building with a length scale of 1/300 is employed to conduct the wind environment experiment. The characteristics of the pedestrian mean wind speed and gust wind speed on the platforms are studied, and the influence of the outdoor platforms with different wind shield heights and forms on characteristics of the wind environment is discussed. This study improves understanding of characteristics of the pedestrian wind environment of outdoor platforms high up on megatall buildings, and lays a solid foundation for its wind comfort and wind safety assessment. The results show that there is significant "funneling effects" in the narrow passageways of two adjacent towers. The wind speed is accelerated, and the maximum pedestrian mean wind speed amplification factor and pedestrian gust wind speed amplification factor reach 1.49 and 1.72, respectively. Moreover, the aerodynamic measures with different wind shields, especially for the outdoor platforms with higher wind shields, are very effective in reducing the maximum wind speeds amplification factor, and improving the whole quality of pedestrian wind environment.