A head-mounted device , comprising: a first housing , defining a first accommodating cavity and a second accommodating cavity that are separated in an upper-lower direction; two second housings ; wherein one of the two second housings extends from a side of the first housing, and the other of the two second housings extends from another side of the first housing opposite to the side of the first housing; the two second housings define two third accommodating cavities connected to the first accommodating cavity, one of the two third accommodating cavities disposed on a left side of the first accommodating cavity, the other of the two third accommodating cavities disposed on a right side of the first accommodating cavity; a portion of the first housing on a side with the second accommodating cavity extends beyond the second housing; and a strap assembly , connected to the first housing and comprising a first headband and a second headband ; wherein an end of the first headband is received in the first accommodating cavity and one of the two third accommodating cavities corresponding to the first headband , and the other end of the first headband is disposed outside the first accommodating cavity; an end of the second headband is received in the first accommodating cavity and the other of the two third accommodating cavities, and the other end of the second headband is disposed outside the first accommodating cavity; characterized in that , the first housing comprises: a first power supply housing ; and a second power supply housing , buckled with the first power supply housing ; wherein a partition plate is arranged in the second power supply housing and configured to divide the first accommodating cavity and the second accommodating cavity; wherein a battery is received in the second accommodating cavity. a first housing , defining a first accommodating cavity and a second accommodating cavity that are separated in an upper-lower direction; two second housings ; wherein one of the two second housings extends from a side of the first housing, and the other of the two second housings extends from another side of the first housing opposite to the side of the first housing; the two second housings define two third accommodating cavities connected to the first accommodating cavity, one of the two third accommodating cavities disposed on a left side of the first accommodating cavity, the other of the two third accommodating cavities disposed on a right side of the first accommodating cavity; a portion of the first housing on a side with the second accommodating cavity extends beyond the second housing; and a strap assembly , connected to the first housing and comprising a first headband and a second headband ; wherein an end of the first headband is received in the first accommodating cavity and one of the two third accommodating cavities corresponding to the first headband , and the other end of the first headband is disposed outside the first accommodating cavity; an end of the second headband is received in the first accommodating cavity and the other of the two third accommodating cavities, and the other end of the second headband is disposed outside the first accommodating cavity; characterized in that , the first housing comprises: a first power supply housing ; and a second power supply housing , buckled with the first power supply housing ; a first power supply housing ; and a second power supply housing , buckled with the first power supply housing ; wherein a partition plate is arranged in the second power supply housing and configured to divide the first accommodating cavity and the second accommodating cavity; wherein a battery is received in the second accommodating cavity. <EOS>