A method and an electronic device for detecting the resolution of a video material are provided. The method is applied to an electronic device, and a calculation circuit of the electronic device executes an AI model. The video material includes multiple frames, and each frame includes multiple sub-frames. The AI model processes multiple pixel data to generate an intermediate resolution corresponding to the pixel data. The method includes the following steps: (A) generating a target sub-frame, the number of pixels of the target sub-frame being smaller than the number of pixels in any frame; (B) inputting the target sub-frame into the AI model to generate the intermediate resolution; (C) storing the intermediate resolution; (D) repeating steps (A) to (C) to generate multiple intermediate resolutions; and (E) determining the resolution of the video material based on the intermediate resolutions.