A training method for an object detection model for a low-quality image, an object detection method for a low-quality image, and a related device are provided. The training method includes: acquiring a low-quality sample image for a target region; inputting the low-quality sample image into a first encoder to obtain an initial feature of the low-quality sample image; inputting the initial feature into a transfer convolutional network, and training the transfer convolutional network to obtain a target convolutional network; obtaining a second target feature for the low-quality sample image; inputting the second target feature into a first detection head, and training the first detection head to obtain an object detection head; and obtaining an object detection model, where the object detection model is used for performing object detection on a low-quality image to be subjected to detection.