1. A method for processing a block to be processed of a urine sediment image, comprising: calculating a variable number of local feature vectors of a block to be processed, wherein the local feature vector is a vector representing a feature of a local location of the block to be processed; classifying the variable number of local feature vectors into a fixed number of clusters so as to obtain a statistical histogram vector of the fixed number of clusters of the block to be processed, wherein the statistical histogram vector reflects the statistical distribution of the variable number of local feature statistical vectors in the fixed number of clusters; and taking the statistical histogram vector as a feature in a feature set of block processing and processing the block to be processed.