Based on investigation of the internal and external research on water pollution source identification methods, combined with heavy metal pollution and regulatory status of trans-boundary river, a framework of sources identification for heavy metal pollution in Chinese trans-boundary water was constructed, which regards space identification as the main line, industry and component identification methods as the important supplementary. Optimization of monitoring investigation method based on optimal search theory, principal component analysis and factor analysis was applied to identify the comprehensive locating of the spatial position, industry type and process of heavy metal pollution sources in the trans-boundary river, which provides a scientific basis for trans-boundary water pollution control and foreign coordination.