A voice enhancement method and apparatus of a smart device and a smart device are disclosed. The method comprises: monitoring and collecting a voice signal sent by a user in real time; determining a direction of the user according to the voice signal; collecting a depth image in the direction of the user; determining a sound source direction of the user according to the depth image; and adjusting a beamforming direction of a microphone array on the smart device according to the sound source direction of the user, and performing enhancement processing on the voice signal.