Abstract: A crash helmet includes a helmet body, a face mask, and a binding device for attaching the face mask to the helmet body. Thus, the face mask is mounted on and removed from the helmet body easily and rapidly by operation of the binding device, so that the crash helmet is assembled and disassembled easily and rapidly, thereby facilitating a user mounting and dismantling the crash helmet. In addition, the face mask is mounted on the helmet body by the binding device without needing a metallic spring to prevent the crash helmet from being inoperative during a long-term utilization, thereby enhancing the lifetime of the crash helmet.