The invention relates to a TMB classification method and system and a TMB analysis device based on a pathological image, comprising: performing TMB classification and marking and pre-processing on a known pathological image to construct a training set; training a convolutional neural network by means of the training set to construct a classification model; pre-processing a target pathological image of a target case to obtain a plurality of target image blocks; classifying the target image blocks by means of the classification model to acquire an image block TMB classification result of the target case; and acquiring an image TMB classification result of the target case by means of classification voting using all the image block TMB classification results. The invention further relates to a TMB analysis device based on a pathological image. The TMB classification method of the invention has advantages of accuracy, a low cost and fast rapid.