DNN model training method and device

The invention discloses a DNN model training method and device, relates to the technical field of machine learning, and can realize joint training of original data sets of companies of two parties onthe premise of not leaking the original data sets of the companies of the two parties. The method comprises the following steps: respectively carrying out unified dimension expansion on dimension vectors in a first data set and a second data set; setting structural parameters of the DNN model; respectively converting data in the first data set and the second data set by using the linear relation coefficient matrix WL and the bias vector bL corresponding to the second hierarchy; performing traversal calculation on each neuron result from the second level to the L < th > level through a loss function and a back propagation function; and correspondingly outputting when the variation of the linear relation coefficient matrix WL and the bias vector bL of each level in the current iteration relative to the last iteratio