The invention discloses a sound source direction judging device, a sound source direction judging method as well as a microphone directivity regulating system and a microphone directivity regulating method. The sound source direction judging device comprises a noise filtering unit, a direction computing unit, and a microphone array composed of three pairs of microphones symmetrically distributed in the positive and negative directions of the X axis, the Y axis and the Z axis, wherein the microphone array is used for receiving sound wave signals of a sound source, and transmitting the sound wave signals to the noise filtering unit; the direction computing unit is used for calculating direction coordinates of the sound source according to the sound wave signals with noise signals filtered out, and judging the direction of the sound source according to the direction coordinates of the sound source. A directivity regulating unit of the microphone directivity regulating system obtains the direction coordinates of the sound source calculated by the sound source direction judging device, regulates the beam direction of the microphone array so that the beam direction is towards the direction coordinates of the sound source, and controls the microphone array to only receive sound waves emitted from the sound source direction, so that voice signals are well received, good voice enhancement and noise attenuation effects are realized, and the effectiveness and reliability of speech communication are realized.