From July to August in 2018 and 2019, 16 Black-necked Crane (Grus nigricollis) juveniles born in Yanchiwan National Nature Reserve, Gansu (hereinafter referred to as Yanchiwan) were installed with satellite trackers. Here we studied the death of these satellite-tracked birds caused by colliding with power lines over the winter and its possible effects. After the satellite trackers were installed, with daily real-time monitoring of the action of the juveniles in the Tracker Client software, we immediately notified local volunteers to confirm if the juveniles had died of colliding with power lines after abnormal actions been found. From January to March in 2019 and 2020, the field survey was carried out in Linzhou County, Tibet, to record the locations of the power lines with which the juveniles collided and the image data of the remains of the Black-necked Cranes. The linear model was used to analyze the changes over time in the number of the Black-necked Cranes in the Yanchiwan from 2013 to 2020. We found that the mortality of the Black-necked Cranes born in 2018 and 2019 were 40.0% and 83.3%. Colliding with power lines was the main reason for the death of the Black-necked Crane juveniles of the population in wintering area. Most of the collision locations were concentrated in the river valley (Fig. 1), where there was a large amount of farmland (Table 2). Before the collision, there were power lines scattering in the active area of the juveniles, and the power lines had interacted with the juveniles (Table 1). The linear model results showed that in the Yanchiwan Black-necked Crane population, except for adults, the numbers of juveniles and subadults were on the rise (Fig. 3). The mortality of juveniles in the wintering area did not seriously affect this population. We recommend to take measures to prevent bird strikes on the power lines in the wintering area, and at the same time, properly guide the setting off of firecrackers to minimize interference with Black-necked Cranes.