Human activity will have an effect on regional landscape patterns and ecological processes. Therefore, it is of great significance to quantitatively depict the landscape ecological effects of human activity. The moving window method was used to quantify the landscape pattern index of Geiju City, Yunnan Province; and an ecological network model based on circuit theory was also implemented. Changes in landscape pattern and connectivity due to human activity in the study area were analyzed between 1990 and 2015. The results show that human activity had a great influence on the landscape pattern of the study area:the SPLIT index increased, along with the degree of landscape fragmentation, and the AI index decreased. A landscape ecological network based on multi-species circuit theory showed that, compared to 1990, in 2015, both the maximum current value and the average current value decreased, indicating that the condition of landscape connectivity had worsened. There were also clearly obvious spatial differences in landscape connectivity between 1990 and 2015. Landscape connectivity in the southern part of the study area remained high, while the landscape connectivity in the central and eastern part of the study area remained low. The ecological corridor network, determined by a zonation model, showed that overall, the corridors tended to be fragmented and their quality was declining. Corridors in the east-central and northern parts of the study area were severely affected:some of the original corridor areas degenerated into non-corridor areas. These results show that human activity led to an increase in the degree of landscape fragmentation, while also reducing the degree of regional landscape connectivity. The research results can provide a scientific basis for future landscape ecological protection and conservation planning during road construction and mineral exploitation in Gejiu City, and can also provide reference methods for similar studies.