The invention discloses a cardiac sound diagnostic system based on a depth confidence network and a diagnostic method of the cardiac sound diagnostic system. The cardiac sound diagnostic system comprises a cardiac sound diagnostic terminal, a network interface module, a database module, a data analyzing module, and a data management module; the data management module is connected with the database module, the data analyzing module and the network interface module at the same time, and the database is connected with the data analyzing module at the same time; the network interface module is in signaling connection with the cardiac sound diagnostic terminal. The diagnostic method is based on a depth confidence network model consisting of restricted Boltzmann machine layering; the diagnostic method comprises the steps: using a patient's cardiac sound file database; training the established depth confidence network by using a layer-by-layer greedy algorithm; inputting the cardiac sound signal to be diagnosed to the depth confidence network model after training; obtaining the final diagnostic result at an output layer and returning to the cardiac sound diagnostic terminal. The cardiac sound diagnostic system based on the depth confidence network and the diagnostic method can realize the remote diagnosis of patient's cardiac sound signals; the operation is convenient and simple, the diagnostic accuracy is high, the cost is low; besides, the device is convenient to maintain and upgrade.