Abstract: Guangdong Province has a large number of nature reserves and a large area. At the same time, Guangdong is a collective forest region in the South and the most populous province in China. There are many human activities in the nature reserve. This paper selected the high-resolution satellite images in 2019 and 2020 as the data source, used object-oriented auxiliary recognition and manual visual interpretation methods to compare the image changes in the early and late stages, identified the land use changes caused by various human activities, and carried out a field verification after combing the newly emerging land type change patches caused by human activities in combination with the central environmental protection supervision and the moving point information of green shield over the years. Then, IHAC (index of human activity change intensity in national nature reserves) was proposed based on the existing HAILS and NRHI indexes and the remote sensing monitoring results were used for trial evaluation. The results showed that IHAC could make an objective and quantitative evaluation of the dynamic impact of new human activities from 2019 to 2020. It built up a foundation for the evaluation of the management effectiveness of nature reserves and the monitoring and early warning of human activities in nature reserves.