The integration of wind speed and direction information into wind turbines operation to achieve attitude correction and pitch control is critical for enhancing energy efficiency and ensuring safe production, so that the LiDAR is widely used in reconstructing the wind field ahead of wind turbines. However, the installation position of nacelle-mounted LiDAR inherently affects the variability and accuracy of wind speed and direction measurement algorithms. In terms of nacelle LiDAR, the wind speed and direction measured in front of LiDAR are not the wind speed and direction of hub, while system noise and outliers further exacerbate measurement discrepancies. To resolve these problems, a linear model of vertical wind shear is proposed to establish relationships between high plane wind speed, low plane wind speed and hub wind speed. Subsequently, the sliding window filtering is adopted to tackle the data of hub wind speed and direction, significantly improving their precision. Finally, the measured error of wind speed and direction are experimentally demonstrated, and can be reduced to 0.5m/s and 10° respectively, the R² between measured and theoretical value is close to zero. This research provides technical guidance and novel idea for the nacelle LiDAR development in wind electrical industry.