Abstract: Wind power is one of the most pivotal components in the renewable energy infrastructure against global climate and fossil-fuel depletion over the past decade. However, the flat and open terrain cannot fully meet the demand to install the wind turbines, particularly with the rapid development of wind power industry. Consequently, a number of turbines are deployed on the complex terrain, such as mountain ridges. Furthermore, the cut slopes can be formed by the hoisting assembly platforms for the wind turbine installation on complex terrains in engineering practice, leading to the varying topography and vegetation coverage. This terrain modification can significantly alter the turbulence characteristics of the wind fields, severely impairing wind turbine power generation efficiency and operational safety. This study aims to explore the turbulent wind fields characteristics over the slope terrain. A two-dimensional ridge terrain was also utilized as the research object. An atmospheric turbulent wind field was established as the inflow condition using narrow band synthesis random flow generation (NSRFG). Large eddy simulations (LES) were subsequently conducted to determine the wind fields over slope terrains. Five excavation positions and five excavation depths were obtained for the hoisting platform. The results show that the wind speed exhibited the following pattern (first increased, then decreased, increases once more, and finally stabilized) with the increasing height at the excavation sites for the five wind turbine installation platforms. When the installation platform was located on the windward side, the wind speed increased and stabilized at the lowest height (compared with the rest locations). As height above the platform increased, turbulence kinetic energy (TKE) demonstrated an initial increase, followed by a decrease, before ultimately reaching a steady state. The minimum TKE peak was achieved to require the lowest height for the TKE stabilization, when the platform was windward positioned, compared with the rest installation positions. There was the minimal influence of the flow separation caused by embankment topography on the turbulent flow characteristics at wind turbine installation platforms under windward siting configurations. Therefore, the windward ridge slope was recommended for the wind turbine installations in the complex terrain. As the excavation depth of the wind turbine installation platform increased, the wind speed fluctuations were intensified at positions closer to the platform surface. At 0.195 times the ridge height excavation depth (0.195H), the wind speed variation range was 1.67 times greater than that at 0.075 times the ridge height excavation depth (0.075H). Among the five excavation depths, the maximum turbulence kinetic energy (TKE) was obtained at 0.165 times the ridge height excavation depth (0.165H), while the minimum peak TKE occurred at 0.075 times the ridge height excavation depth (0.075H). The turbulent flow characteristics shared the minimal interference from the slope terrain-induced flow separation, when the installation platform was excavated to 0.075 times the ridge height (0.075H). Therefore, the excavation depth was the lower tip of the rotor plane over the summit elevation for the wind turbine installations in sloped terrain. This configuration can be expected to minimize the flow separation disturbances in the incoming airstream.