The invention provides an improvement-based KNN (K Nearest Neighbor) text classification method. The method comprises the following steps: preprocessing a training text, computing the feature vector of each training sample, and constructing a feature vector spatial model of a training set; defining a density and a distance, defining a density and a distance, defining a whole sample space into a plurality of spherical regions and outliers according to types, and storing as a training set library; during testing, judging whether a text to be tested falls into a certain spherical region, judging the type of the text to be tested according to a corresponding mark number, otherwise, using the outliers and the center point of each sphere as a training set library, calling a KNN algorithm, and judging the type of the text to be tested. By adopting the method provided by the invention, the classification speed, classification accuracy and data skew sensitivity are considered. The method can be well applied to the classification problem of non-spherical distribution, and is particularly suitable for a text classification problem having a high-dimension feature vector and a distribution irregularity feature.