A paper roll holder, a printer having the same and a paper end detecting mechanism are disclosed. The paper roll holder comprises a turning plate, which upper surface forms a first arc groove close to a rotation centre and a second arc groove far away from the rotation centre; an elastic element, providing a rotating torque to the turning plate so that the turning plate turns from an initial position to an upturning position during the printing and consuming of a paper roll; and a sensor, arranged in the second arc groove of the turning plate for detecting the paper. Wherein, the turning plate has the initial position suitable for supporting a large paper roll in the second arc groove and the upturning position suitable for supporting a small paper roll in the first arc groove. When the printing paper roll is near end, along with rotation of the turning plate, the small paper roll is limited in the first arc groove so as to prevent the small paper roll from moving in the paper house during printing. When the residual amount of the printing paper is less than the distance between the sensor and the printing mechanism, the sensor can promptly and accurately send out a paper lack signal, thereby improving the reliability of paper detection by the sensor.