The values of analytical continuation at different depths from the potential field downward constitute the continuation field, on which the principal component analysis is made. The theoretical model calculation shows that, under the condition without any priori information, the energy weight value resolved from the continuation field or the maximum characteristic value of the matrix related to the continuation field can be used to judge the position of the potential field source, thus determining the burial depth of the geological body. Such organic combination of the determined signal analytical method for potential field analytical continuation with the stochastic signal analytical method for principal component analysis provides a new channel for the inversion of geophysical potential field.