The invention discloses an automatic excavation system for analogous customer groups, which comprises a data preprocessing and cleaning device, an unstructured information extractor, a fusion search engine, an excavation target generator, a data warehouse, a relevance analyzer, a tendency analyzer, a customer lose analyzer, a classification analyzer, a cluster analyzer, an isolated point analyzer, customer enterprise characteristic analyzer, a commercial activity analyzer, a customer enterprise credit analyzer, a customer enterprise loyalty index analyzer, a customer enterprise attention analyzer, a customer enterprise marketing analyzer and a result summarization and visualization module. With the system, the contracted customer enterprises are taken as cases, and the analogous customer groups are deeply and accurately excavated in real time, so that value-added services of analogous customer enterprise groups can be immediately provided for users according to rules of a case expansion method.