The invention involves a method and a device that converting the summer-autumn tea concentrate to instant powdered black tea by oxidation reaction. The method is comprised of the following steps: pushing the summer-autumn tea concentrate and oxygen into a long spiral pipe, making them flow, impact, and mix in a high speed which can achieve a high efficient oxidation; the intelligent control of the oxidation process can be realized by the change of the color of the concentrate in the oxidation process; the color value of the concentrate can be detected in real time by peristalsis pump, which flows into the color detection channel based on the multi spectral flash LED light transmission technology; the oxidation can be stopped immediately when the detected chromatic value is within the range of the preset target chromatic value. The patent also provides a device for aerating oxygen, including summer-autumn tea concentrate liquid storage tank, gas-liquid mixing pipe loop and color pipeline detection circuit. The process and the device can realize the oxidation of summer-autumn tea concentrate in a fast, uniform and sufficient way, and can also achieve the process that can improve the quality of instant black tea.