An adjustable helmet and a massager comprising the helmet. The adjustable helmet comprises a helmet body (1). The helmet body (1) comprises a front casing (11) and a rear casing (12). The front casing (11) and the rear casing (12) are connected by means of two racks (13) at two joints. An adjusting mechanism (2) is arranged on the helmet body (1) and comprises a knob assembly (21) and a locking assembly (22). The knob assembly (21) comprises a knob outer ring (23), a knob shell (24) and a ratchet wheel set (25). The ratchet wheel set (25) comprises a ratchet wheel (251) and a ratchet wheel seat (252) that is matched with the ratchet wheel (251). Two groups of ratchet rings (2521) are arranged on the ratchet wheel seat (252), and two driving teeth (2511) matched with the two ratchet rings (2521) respectively are arranged on the ratchet wheel (251). The locking assembly (22) comprises a rotation shaft (26), a gear (27) and a knob buckle (28). The adjusting mechanism (2) uses the ratchet wheel (251) for driving, so that forward and backward adjustment can be performed by means of the knob outer ring (23) to adjust the helmet opening diameter, and the helmet is convenient to adjust the locking assembly (22) is arranged in the helmet, so that loosening of the helmet can be prevented effectively and when the helmet is used in the massager, the massage comfort level controllability is high, and the massager is convenient to operate.Linvention concerne un casque réglable et un appareil de massage comprenant le casque. Le casque réglable comprend un corps de casque (1). Le corps de casque (1) comprend un boîtier avant (11) et un boîtier arrière (12). Le boîtier avant (11) et le boîtier arrière (12) sont reliés par deux crémaillères (13) au niveau de deux articulations. Un mécanisme de réglage (2) est disposé sur le corps de casque (1) et comprend un ensemble bouton (21) et un ensemble de verrouillage (22). Lensemble bouton (21) comprend une bague extérieure (23) de bouton, u
