Cognitive Map (CM) is a new kind of method of knowledge management, which has many advantages such as: it is relative easy to use for representing structured knowledge, the inference mechanism can be computed by numeric matrix operation, etc. However, in order to exhibit these advantages about CM, the first step is that the corrected CMs must be obtained. Traditional approaches for obtaining the CMs, including questionnaire method, brainstorming method, and sample learning method, always rely on experience of domain experts. Because these methods put much emphasis on the subjective factors and neglect the objective data resources, they always lose some information. Therefore, this paper proposes a new methodology of mining the CMs based on data resources, which mainly includes database preprocessing technology, optimization algorithm for weight coefficients, and simplification strategy for CMs. The experimental results show that: the new method can mine all possible relationships among all nodes to form the CMs, and can also simplify it according to the significant degree of those relationships; the CMs mined by the new method has more information than the CMs obtained by traditional approaches.