The invention discloses a kitchen ventilator with an oil-smoke separation device and a noise reduction device and a noise reduction method. The kitchen ventilator comprises a kitchen ventilator body,the three-dimensional space sound field noise reduction device for active noise reduction, and the oil-smoke separation device for absorbing and separating lampblack particles. The three-dimensional space sound field noise reduction device is assembled into the kitchen ventilator body. The oil-smoke separation device is assembled into the kitchen ventilator body in a driving mode.The three-dimensional space sound field noise reduction device is provided with a noise collection sensor and a noise reduction body. The noise collection sensor is used for detecting decibel of noise sources in the kitchen ventilator body. The noise reduction method includes the steps of decomposing a noise signal into multiple sub-band signals, acquiring a band-pass filter weight vector through conversion, converting the acquired band-pass filter weight vector into a corresponding loudspeaker sound field, transmitting a constant-strength sound wave signal to a corresponding loudspeaker, and reducing or eliminating noise waves generated by the kitchen ventilator through sound waves generated by the corresponding loudspeaker to reduce noise. The kitchen ventilator has the advantages that the technical problem of conflict between the noise and performance is solved, and on the premise of not sacrificing lampblack suction performance of the kitchen ventilator, the noise generated during operation of thekitchen ventilator is low and does not cause negative influence on users physiologically and mentally.