Embodiments of the invention disclose a document topic determination method and apparatus, which is used for determining a topic of a target document. The method comprises the steps of training a training document set, a training word set and a tag set previously according to a Labeled LDA model to obtain a word-tag conditional probability set, and obtaining a word probability set according to the training word set; then obtaining the target document to be subjected to topic determination and a target word in the target document; from the word-tag conditional probability set, searching for a word-tag conditional probability corresponding to the target word; from the word probability set, searching for a word frequency corresponding to the target word; according to the word-tag conditional probability and the word frequency corresponding to the target word, obtaining a tag-target document conditional probability corresponding to the target document; and determining the topic of the target document according to the tag-target document conditional probability corresponding to the target document.