The invention discloses a hair straightener device. The hair straightener device comprises a shell and an electrical connection head jacked into the shell for cooperative connection. An inner groove expanding left and right is formed in the shell. The right end of the inner groove and the exterior of the shell are connected with a splice groove, a partition plate fixedly connected with the shell is arranged at the position, located above the splice groove, of the right end of the inner groove, a groove expanding upwards is formed in the partition plate, the left end of the groove is connected with the inner groove, the right end of the groove is connected with the exterior of the shell, and the lower portion of the groove is connected with the splice groove. The hair straightener device is simple in overall structure, low in production cost, safe and stable in power supply and easy to operate, existing electric shock accidents in life are effectively reduced, the life and property safety of people is guaranteed, the power cutoff accident, caused by mistaken kicking and colliding, of a hair straightener can be avoided, the service life of the hair straightener is effectively protected, and the hair straightener device is suitable for use and popularization.