Abstract: A helmet with a built-in automobile data recorder is provided, including a helmet shell, with a motherboard and a deputy motherboard thereon, a flat cable is connected there between. The motherboard has a lens and a flat cable joint, and the deputy motherboard has a lithium battery, a charging data interface, a function key, and a working lamp, a reset key and an abnormal lamp being arranged from top to bottom. A sealing cover where the motherboard is fixed by screws is arranged on top of the helmet shell, the lens is mounted on top of the helmet shell, and the deputy motherboard is mounted on a side of the helmet shell. The embodiments have the following advantages: 1. reasonable structure and built-in automobile data recorder, 2. powerful functions and high stability, 3. no installation and convenient use, 4. direct connection with a portable power source.