Abstract: A handle-adjusting device for adjusting position of a handle relative to a vehicle frame includes a valve cylinder with a valve rod, and a control rod that is formed with a pressing face and a release face. When the control rod is operated to align the pressing face with an upper end of the valve rod, the valve rod is disposed at a retracted position so as to enable rotation of the handle relative to the vehicle frame. When the control rod is operated to align the release face with the upper end of the valve rod, the valve rod is disposed at the extended position so as to prevent rotation of the handle relative to the vehicle frame.