A cochlea hearing aid device for helping users to hear includes a cochlea electrode and a driver circuit. The driver circuit has a casing for installing at a through hole on an eardrum of the user. The cochlea electrode is installed within the cochlea of a user. The driver circuit is connected to the cochlea electrode in order to signal process a voice data and provides a corresponding driving signal for cochlea electrode. Therefore, the neural cells in the cochlea of the user will be stimulated and helped the user to hear.