Geochemical abnormal region delineation method

The invention provides a geochemical abnormal area delineation method, which comprises the following steps of: performing gridding division on a research area according to lithologic change and topographic and geologic characteristics of exposed rocks, uniformly collecting experimental samples in each grid according to a certain interval, and performing experimental test indoors to obtain geochemical components of the samples; carrying out principal component analysis to obtain a mineralization principal component score, and calculating a drainage basin coefficient according to the mineralization principal component score; and a geochemical anomaly intensity index AI is defined, an AI value is obtained through calculation according to the mineralization principal component score and the drainage basin coefficient, a threshold value is set, geochemical anomaly region levels are divided, and an anomaly region is delineated. The method is rigorous in principle, high in operability and high in delineation precisi