Target region dose field forming method and system of stereotactic radiotherapy equipment

The invention provides a target region dose field forming method of stereotactic radiotherapy equipment. Comprising the following steps: S1, determining a target contour, a target region contour and an endangered region contour of a target, and arranging target spots; s2, forming a radiation source motion arc; s3, obtaining a first arc segment in which the distance between an intersection point of a ray source ray and the target contour and the target spot is greater than a preset value and a second arc segment in which the ray source ray intersects with the contour of the endangered area of the target; s4, setting ray constraint of a ray source in the first arc section and the second arc section, and distributing the ray dose of each target spot based on the total ray dose of the target spots; and S5, adjusting one or more of the position, the number, the size and the ray irradiation duration of the target spots to enable the ray dose to be uniformly distributed and to be matched with the contour of the targ