The invention discloses a picking robot target autonomous recognition method adapted to sudden changes in illuminance, the steps are as follows: S1, calculate the optimum brightness V fit ; S2, the camera collects real-time images; S3, calculates the frame brightness V of the real-time image; S4, calculates the brightness compensation value b of the real-time image; S5, obtains the compensated image; S6, establishes the HSV model; S7, determines the target fruit. And a picking robot target autonomous recognition system adaptable to sudden changes in light intensity, including a fruit and vegetable picking robot, a controller, a camera and a light sensor are installed on the fruit and vegetable picking robot. The hood is equipped with LED lights under the camera or under the claws of the mechanical arm of the fruit and vegetable picking robot. The invention performs supplementary light processing on the image, so as to minimize the influence of light mutation and provide accurate image information for the visual system to recognize the fruit.