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.本創作屬於按摩器，提供一種可調式頭盔，包括頭盔本體，頭盔本體包括前殼體以及後殼體，前殼體與後殼體的兩連接處之間採用兩齒條連接，頭盔本體上還設有調節機構，調節機構包括旋鈕元件以及鎖緊元件，旋鈕元件包括旋鈕外圈、旋鈕外殼以及與棘輪組，棘輪組包括棘輪以及與棘輪配合的棘輪座，棘輪座上設有兩組棘齒圈，棘輪上設有可分別與兩棘齒圈配合的兩撥齒，鎖緊元件包括轉軸、齒輪以及旋鈕鎖扣；還提供一種頭盔式按摩器，包括上述頭盔。本創作的調節機構採用棘輪傳動，可使旋鈕外圈進行順逆雙向調節以實現頭盔口徑大小的調節，比較方便，其內設鎖緊元件可有效防止頭盔鬆動的現象，將其應用於按摩器中時，按摩舒適度可控性高，操作方便。
