A signal identifying method includes obtaining signal characteristics of a current frame of input signals; deciding, according to the signal characteristics of the current frame and updated signal characteristics of a background signal frame before the current frame, whether the current frame is a background signal frame; detecting whether the current frame serving as a background signal frame is in a first type signal state; and adjusting a signal classification decision threshold according to whether the current frame serving as a background signal frame is in the first type signal state to enhance the speech signal identification capability.