Abstract: The stress change characteristics of polar sea ice are important parameters for the evaluation of sea ice mechanical properties and the construction of sea ice dynamics models. They are also the key environmental elements required for engineering applications in polar regions, and there is still a gap in its long-term continuous monitoring. In order to explore the characteristics of sea ice stress changes during the freezing-thaw cycle of sea ice in polar seas and analyze the impact of environmental changes on the sea ice, a polar sea ice stress monitoring buoy was designed and developed, which is mainly composed of meteorological observation module, sea ice temperature profile observation module, sea ice stress observation module, which can enable long-term continuous observation of ice surface meteorology, sea ice temperature and sea ice stress. The sea ice stress observation module uses the vibrating wire strain gauge as the observation sensor, and through the strain comparison of different test experiments, there are differences in the change trend and fluctuation range of the ice strain data under different layers and observation angles, and it is determined that the sea ice stress observation module adopts the direct measurement method in the ice with the sensor base structure, and the vibrating wire strain gauge with 0°, 45°, and 90° horizontal observation angles is vertically deployed at 50, 80, and 110 cm in the ice layer to obtain different vertical horizons. To provide data support for understanding the mechanical change characteristics of sea ice, the sea ice stress change data from different horizontal observation angles are provided.