The invention relates to the technical field of image processing, and discloses a G-band chromosome HDR image reconstruction method, which comprises the training steps of a dequantization network model, a linearization network model and a detail reconstruction network model, and the step of reconstructing an HDR image by using the trained models. According to the method, three neural network models, namely a de-quantization network, a linearization network and a detail reconstruction network, are designed, and a training set is formed by utilizing an actual G-band chromosome HDR image and a corresponding real LDR image, so that the training of the three neural network models is completed; performing three steps of de-quantization, linearization and overexposure region detail reconstructionon a real LDR image by using the trained model, and finally completing a task of G-band chromosome HDR image reconstruction; according to the method, reconstruction of the HDR image is completed onlythrough one LDR image, so that G-banding chromosome characteristics are more obvious, subsequent analysis is facilitated, artifacts do not appear in the reconstructed HDR image, and the quality of the image is higher.