The invention discloses a 
lung lobe segmentation method and 
system based on a three-dimensional 
convolutional neural network. The method comprises the following steps: constructing a training image 
data set of 
lung lobe segmentation; constructing a 
lung lobe segmentation network based on a three-dimensional 
convolutional neural network, performing network training, preprocessing the training imagedata set, and outputting a category probability graph to which each pixel belongs after the training is completed; calculating the loss of the category probability graph to which each pixel belongs by adopting a Dice Loss 
loss function, and weighting the loss of a plurality of category probability graphs to obtain total loss; setting weight attenuation and learning rate attenuation, and trainingthe network until the network converges; preprocessing a to-be-detected image, inputting the preprocessed to-be-detected image into a trained 
lung lobe segmentation network, and outputting a prediction result; and restoring the prediction result subjected to post-
processing to the original input size of the to-be-detected image to obtain a final segmentation result. The 
lung lobe segmentation result can be obtained through preprocessing and network reasoning, end-to-end design is achieved, and the 
lung lobe segmentation efficiency and precision are improved.