Collimator and CT machine

The invention discloses a collimator and a CT machine, belongs to the technical field of medical equipment, and aims to solve the technical problem that an existing collimator occupies too large CT internal space. Wherein the collimator comprises a collimator main body, the collimator main body is provided with a first collimation surface facing or backing on to the bulb tube and a second collimation surface facing or backing on to the bulb tube, the curvature of the first collimation surface is larger than that of the second collimation surface, the first collimation surface and the second collimation surface are arranged in a staggered mode, and the collimator main body is provided with a ray channel penetrating through the collimator. The ray channels are distributed on the first collimation plane and the second collimation plane. The space occupied by the portion, corresponding to the second collimation face, in the collimator body is smaller than the space occupied by the portion, corresponding to the first collimation face, of the collimator body, so that the structure of the collimator is relatively compact, and the space occupied by the collimator is smaller when the collimator is arranged in the CT machine. The projection formed on the detector after the X-ray passes through the ray channel corresponding to the first collimation plane is closer to a rectangle, so that the part of image has a better imaging effect.