[Objective] The relationship between vegetation cover changes and extreme climate in Shandong Province was studied in order to provide a reference for regional vegetation ecological maintenance. [Methods] Based on the 1982—2021 long-term NDVI data set obtained from AVHRR-GIMMS NDVI interpolation of MODIS NDVI, the temporal and spatial changes of NDVI in Shandong Province were analyzed, and the daily data of 96 weather stations in the province were combined to study the response of NDVI to extreme climate. [Results] ① NDVI in Shandong Province and its subregions showed an overall strong and sustained upward trend, with an average growth rate of 0.013/10 yr (p＜0.001) for the entire province. NDVI was generally high in the west and low in the east, and high in the south and low in the north. On the spatial scale, the vegetation cover was mainly improved and basically unchanged in strong sustainability. ② On the whole, NDVI showed a significant positive correlation with annual and monthly extreme temperature and extreme precipitation indices; a significant negative correlation with the cold index; and no significant correlation with GSL and DTR. Western Shandong Plain was mainly affected by extreme temperature, and other subregions responded greatly to both extreme temperature and extreme precipitation. ③ The response of NDVI to extreme climate exhibited obvious hysteresis, and the hysteresis of extreme temperature was stronger than that of extreme precipitation. [Conclusion] The overall vegetation coverage in Shandong Province was developing in the direction of continuous improvement. NDVI exhibited an obvious response to extreme climate. Extreme high temperature and extreme precipitation promoted vegetation growth, while extreme low temperature mainly inhibited vegetation growth. There was a lag in the response of vegetation cover changes to extreme climates.