The unique geographical location of Lake Qinghai not only plays a role as a natural regulator for the climate around the lake, but also has abundant resources on the shoreline. Accurate and timely grasp of the shoreline dynamic changes of Lake Qinghai is of great significance to protect the ecological environment along the lake. Based on Landsat MSS/TM/OLI remote sensing images from 1973 to 2018 and water level data from 1961 to 2017, this paper studied the changes of shoreline and its impact on bird habitats. At the same time, the main factors affecting shoreline changes were discussed in combination with area, water level and meteorological data. The main conclusions are as follows:(1) In the past 45 years, the areas with the greatest changes in the shoreline of Lake Qinghai have been the Lake Shadao on the east coast, the Bird Island on the west coast, the Tiebuka Bay and the entrance to the Shaliu River on the north coast. Especially since 2004, the shoreline in the Bird Island had the largest retreat distance (5.52 km) and bird habitat expansion was about 97.94 km², which provided a better habitat for birds. (2) The length of the Lake Qinghai shoreline gradually extended at a rate of 0.88 km/a from 1973 to 2018. Before 1997, the length of the shoreline showed a relatively steady upward trend. Then, it showed a fluctuating downward trend from 1997 to 2004. After 2004, it showed a sharp increase in volatility, and the shoreline tortuosity also showed the same trend. (3) The overall shoreline length and tortuosity were not significantly affected by water level and area, but they responded differently to the dynamic changes of Lake Qinghai under different water levels. Especially when the water level was less than 3193.3 m or the area was less than 4249.3 km², the tortuosity of the shoreline showed the same trend with the change of water level and area. While the water level was higher than 3193.3 m, the tortuosity of the shoreline had been increasing, and the greater the rate of water level rise, the greater the annual variation of tortuosity. (4) The water level decline and land desertification of Lake Qinghai from 1973 to 2004 were the direct causes of lakeshore changes. Human activities and grassland degradation accelerated the change of lake shoreline. After 2004, as the water level of Lake Qinghai rebounded and the area expanded, the coastline gradually receded, especially during 2017-2018.