PROBLEM TO BE SOLVED: To provide a dental X-ray imaging system in which X-ray irradiation can be made only in a range equal to a sensor frame on X-ray irradiation, and thereby to solve a drawback of a conventional system by the dental X-ray imaging system with less exposure dose and scattering dosage.SOLUTION: A sensor is held in an imaging part in an oral cavity A through a holder 5 of the sensor C. Also, while a head 2 of the X-ray apparatus D is opposed and disposed to a marker 6 provided in the holder 5 of the sensor C, an opening degree of a collimator 39 and a rotation direction of the collimator 39 equipped in a cone 3 of a head 2 are controlled through a control unit of the collimator 39 by a CCD camera 7 equipped in the cone 3 of the head 2. Thereby, it is controlled and opposed in sizes, shapes, holding positions, and angles of the sensor C held by the holder 5 in the oral cavity A, and the imaging part F in the oral cavity A is imaged while applying the X-ray beam only in a sensor frame range of the sensor C.