Landslide monitoring plays an important role in predicting, forecasting and preventing landslides. Quantitative explorations at the subject level and fine-scale knowledge in landslide monitoring research can be used to provide information and references for landslide monitoring status analysis and disaster management. In the context of the large amount of keyword co-occurrence network information, it is difficult to clearly determine and display the domain topic hierarchy and knowledge structure. This paper proposes a landslide monitoring knowledge discovery method that combines the K-core decomposition and Louvain algorithms. In this method, author keywords from the literature are used as nodes to construct a weighted co-occurrence network, and a pruning standard value is defined for K. The K-core approach is used to decompose the network into subgraphs. Combined with the unsupervised Louvain algorithm, subgraphs are divided into different topic communities by setting a modularity change threshold, which is used to establish a topic hierarchy and identify fine-scale knowledge related to landslide monitoring. Based on the Web of Science, a comparative experiment involving the above method and a high-frequency keyword subgraph method for landslide monitoring knowledge discovery is performed. In the resulting 5-core network subgraph of landslide monitoring keyword co-occurrence, 17 community structures can be identified, and the degree value and density of subcommunities are analysed by taking the community with the largest proportion of nodes as an example. The results show that the retention time of the proposed method is significantly lower than that of the traditional method.