A voice control system and a voice control method for an automatic door are provided. The voice control system includes a sound detection device, a storage device, a first determination circuit, a second determination circuit and a control circuit. The sound detection device detects a sound signal of a sound source, the storage device includes a voiceprint database that includes reference voiceprint features. The first determination circuit analyzes a voiceprint feature of the sound signal and compares the voiceprint feature with the reference voiceprint features. The second determination circuit determines whether a velocity of the sound source falls within a reference speed range according to a frequency variation of the sound signal that matches one of the voiceprint features. In response to the velocity of the sound source within the reference speed range, the control circuit controls the automatic door to be in an open state.