The invention provides a cross-project defect influence analysis method based on a program dependency relationship and symbolic analysis. The cross-project defect influence analysis method comprises the following steps: 1) acquiring program source codes of different projects and multiple versions in the same software ecosystem; 2) extracting a calling relationship from a program source code of each project basic version, and constructing an ecosystem basic dependence network; 3) obtaining code changes from program source codes of other versions of each project, and constructing a version-sensitive ecosystem dependent network; 4) for a given cross-project defect, under the condition that an upstream error method of the cross-project defect is known, selecting a candidate downstream module;5) for each candidate downstream module, carrying out code preprocessing; 6) performing symbol coding on each preprocessed candidate downstream module; and 7) carrying out constraint solving on each downstream module after symbol coding, and if a solution exists, prompting a developer that the module is possibly influenced by a given cross-project defect. According to the method, the problems thatat present, cross-project defect influence analysis is lacked, and a downstream project affected module cannot be prompted are solved, so that the design of a cross-project defect repair scheme is guided, the quality of defect repair patches is improved, and healthy development of a software ecosystem can be better controlled and managed.