Novel X-ray tube structure capable of controlling size of focus

The utility model discloses a novel X-ray tube structure capable of controlling focus size, which comprises a cathode emission disc, a first solenoid is arranged at the lower end of the cathode emission disc, and a first electron beam envelope is arranged on the inner side of the first solenoid below the cathode emission disc. According to the novel X-ray tube structure capable of controlling the size of the focus, the size of the focus is adjusted through joint cooperation of the first solenoid and the second solenoid, during adjustment, the size and the angle of the focus are two variables coupled together, so that the angle also changes, and in order to more conveniently adjust, the size of the focus is adjusted. The beam is controlled by using the magnetic fields of the first solenoid and the second solenoid, so that the direction and the size of an electron beam hit on the target disc are adjusted by accurately controlling the change of the magnetic fields, the purpose of quickly adjusting the size and t