The invention discloses an accelerating installation and method of K-nearest neighbor, which relates to the field of information retrieval, data mining and computer architecture, the device comprises a control module, used to control each module in the accelerating installation; an address calculation module, used to acquire the address of the training sample; an Euclidean distance calculation module, used to calculate distance when searching K-nearest neighbor; a result module, used to store and transmit the distance; a sequencing module, used to implement K-nearest neighbor sequencing for the distance. Wherein, the result module transmits the distance to the sequencing module, and sends the signal of the next address to the address calculation module for calculation, the address calculation module receives the signal and calculates the address of the next training sample, and the control module clears the contents in the result module. The accelerating installation and method of K-nearest neighbor adjusts KNN algorithm with samples under different dimensions through component increasing and decreasing, and meets different demands of sample algorithm under the same dimension by adjusting degree of parallelism.