The invention provides a mounting device. The mounting device comprises a base structure, a connecting structure and a locking ring; the base structure comprises a supporting seat, a clamping part anda sealing part; the supporting seat is in a circular ring shape; the clamping part is positioned at the top of the supporting seat; an mounting opening is formed in the clamping part; an mounting cavity is formed by an inner cavity of the clamping part and an inner cavity of the supporting seat; the inner diameter of the top of the clamping part is larger than the inner diameter of the bottom ofthe clamping part; the locking part comprises a locking part and a connecting part; the locking part is arranged at the top of the supporting seat; the connecting part is arranged at the top of the locking part; the size of the inner wall of the connecting part is larger than that of the inner wall of the locking part; the size of the inner wall of the locking part is gradually reduced relative tothe size of the inner wall of the connecting part; the sealing part is arranged in the mounting cavity; and the sealing part is in a circular ring shape. The mounting device is high in universality,and convenient to dismount, replace and clean.