A front-opening buckle type adjustable underwear comprises a first cup, a second cup, a first shoulder strap, a second shoulder strap, a body and an adjusting component. The body is connected with the first cup and the second cup, and is positioned at the rear side of the first cup and the second cup, and the other end of the first shoulder strap and the other end of the second shoulder strap are connected with the body. The adjusting part comprises a first adjusting belt, a second adjusting belt, a connecting part and an adjusting part, wherein the first adjusting belt and the second adjusting belt have elasticity, one end of the first adjusting belt is connected to the first cup, one end of the second adjusting belt is connected to the second cup, the other ends of the first adjusting belt and the second adjusting belt are respectively provided with a connecting part, the first shoulder belt is close to the first cup and the second shoulder belt is close to the second cup, the connecting part of the first adjusting belt is connected with one of the adjusting parts on the second shoulder belt, the connecting part of the second adjusting belt is connected with one of the adjusting parts on the first shoulder belt, and the first adjusting belt and the second adjusting belt are crossed.