The invention discloses an information retrieval method based on a Bayesian classification algorithm in the technical field of information processing, which comprises the steps of: selecting a data sheet from a relationship database, establishing an information retrieval model; deriving a sample set from the information retrieval model, dividing the sample set into a training data set and a testing data set; selecting relevant fields from the information retrieval model to be used as a classification attribute of the sample set, determining the class of the classification attribute and calculating the prior probability of the class of the classification attribute; calculating the posterior probability of samples; calculating the class probability of the samples according to the Bayesian formula; classifying the samples according to the class probability of the samples, and generating a data classification set; and making the information retrieval operation in the data classification set by a user. The invention applies the Bayesian classification algorithm to the actual information retrieval, thereby effectively improving the accuracy of the information retrieval.