Convolutional neural network(CNN) is used to index the metadata of Chinese characters in ancientbooks in the field of digital humanities, so that the recognition of Chinese characters in ancient books istransformed into the classification of CNN. As a result of the absence of training sets,data generation technology isused for model training, and then for the recognition of Chinese characters in ancient books. In detail, theTensorFlow platform is used to generate about 240,000 training samples for 773 Chinese characters, and theadopted network model can be used to pick out those unrecognizable character pictures automatically. Then,theunrecognizable character pictures would be transferred for manual recognition,which would be more reliable. Inshort,though still a semi-automatic tool,it can save the manpower cost to a certain extent in the indexing of digital humanistic metadata.