The utility model discloses an adjustable handlebar for a mountain bike, which comprises a handlebar body and rubber jackets, the rubber jackets are sleeved on handlebar bodies on two sides of the handlebar body in a clamping manner, the adjustable handlebar further comprises a handlebar adjusting mechanism, and the handlebar adjusting mechanism comprises an expanding column groove, a blocking block, a
threaded rod, a threaded cylinder, a hexagonal rotating block, a double-plate hoop, an inner layer sleeve, an outer layer sleeve and a magnetic attraction fixed block. An expanding column groove is formed in the outer end, in the rubber sleeve, of the handlebar body, the handlebar adjusting mechanism is arranged at the handlebar transverse position of the handlebar body, the expanding column groove of the handlebar adjusting mechanism, a
threaded rod and a threaded cylinder are combined, a detachable double-plate clamp is matched, the length of the handlebar transverse is expanded as needed, and a user can adjust the length of the handlebar transverse position according to the
shoulder width and the palm size of the user. The holding position is accurately adjusted by rotating the hexagonal rotating block, and the clamping hoops can be added in a superposed manner, so that different distance increasing requirements can be flexibly met, the problem that holding is limited due to accessory installation at the handlebar body is effectively solved, and the riding comfort is greatly improved.