The invention provides a domain self-adaption method based on a triple and difference measurement, which comprises the following steps of: randomly extracting samples from a target domain to form a target domain batch, and inputting a target domain batch to obtain sample features; inputting the sample features into a multi-classifier, and performing entropy minimization processing; inputting the sample features into a multi-binary classifier at the same time, and determining k critical samples and k pairs of similar classes according to the output; then, screening effective samples by utilizing triplet loss to construct a source domain batch, and training a multi-binary classifier and a multi-classifier through an extracted source domain batch sample; and finally, sending the target domain batch and the source domain batch into the domain adversarial network, and carrying out domain alignment operation. According to the method, a triple loss function is used, the margin between positive and negative sample pairs in the loss is reasonably designed, and domain alignment is carried out by using a domain adversarial network, so that sample distribution of a source domain and a target domain tends to be consistent, and samples, close to a classification boundary, of the target domain are indirectly far away from the boundary; therefore, the samples of which the target domains are close to the classification boundary can be correctly classified.