Disclosed an HDR television and a method for regionally dimming, the HDR television including a display screen, an offset calculation module, a constant-current driving and controlling module, a plurality of constant-current driving circuits, a plurality of light bars, an image processing MCU, and a memory; the display screen is divided into a plurality of regions, and the plurality of light bars are respectively distributed in the plurality of display screen regions; the image processing MCU is configured to output a grayscale signal; the offset calculation module is configured to acquire brightness information of each region of the display screen, calculate a reference offset of each region according to the brightness information of each region, and store the reference offset in the memory; the constant-current driving and controlling module is configured to read the reference offset in the memory.