Abstract: A head worn displaying device of the disclosure includes an optical reflective lens, a display screen and a cover. The optical lens and the display screen are mounted under the cover, and the cover may be similar to a hat tongue located ahead of the forehead of a user. The display screen can be integrated in a mobile phone, and a holder such as a clamper set is used to clamp the mobile phone. The angle of the optical lens can be adjusted, for example, by using a sliding groove and a magnetic hinge which are located at a front end of the hat tongue. The magnetic hinge slides in the sliding groove to adjust a distance between the display screen and the optical lens.