A method and apparatus for training a search model, and a method and apparatus for searching for a target object are provided. The method may comprise: obtaining, based on sample query information, a first sample data set used to train the search model. The method may further comprise: determining, based on a pre-constructed knowledge base, additional query information associated with the sample query information. In addition, the method may further comprise: obtaining, based on the additional query information, a second sample data set used to train the search model, wherein the second sample data set is different from the first sample data set. Moreover, the method may further comprise: training the search model based on the sample query information, the first sample data set, and the second sample data set.