The present invention relates to a variable pin-hole type collimator applied to a radiation imaging device. The variable pin-hole type collimator comprises: a hole forming module having a plurality of apertures which are stacked in a direction of irradiation such that each aperture defines a penetrating-space through which radiation passes; a plurality of driving modules which are configured that each driving module varies each penetrating-space of the aperture independently; and a collimating controller to control the driving modules such that each penetrating-space of the aperture varies independently and the hole forming module forms a pin-hole through which radiation passes. Therefore, a collimator having various types can be embodied by the variation of the pin-hole shape.