The invention relates to a method for preventing single-CT saturation of a 3/2 wiring mode from causing distance protection misoperation, comprising the following steps: judging whether a fault occurs to a near end and whether the fault is a metallic fault based on the through current and fault voltage of a fault side switch and a middle switch, and performing CT saturation judgment if the fault is a near-end metallic fault; and judging whether the fault is an external fault according to the through current of the fault side switch and the middle switch, and performing locking protection to prevent distance protection misoperation in the period of CT saturation when the fault is judged to be an external fault. Near-end metallic fault judgment and CT saturation judgment are carried out together, so that distance protection misoperation caused by CT saturation before the external fault is cleared can be prevented effectively, and distance protection misoperation due to the fact that an internal fault is misjudged to be CT saturation can be prevented. Therefore, the security and stability of the power system are improved.