The invention provides a well leakage patching system and a patching method, wherein the well leakage patching system comprises a patching device, a feeding device, and a detachable connector. The patching device is provided with a first state and a second state, wherein the first state is used to enter an oil well after compression and the second state is used to be attached to the inner wall ofthe oil well to seal the well leakage after release. The detachable connector is provided with a third state and a fourth state, wherein the third state is used to connect the patching device and thefeeding device, the fourth state is used to separate the patching device and the feeding device. When in use, the well leakage patching system is lowered, the lowered position of the patching device corresponds to the position of the well leakage, and after the position of the patching device is determined, the detachable connector is switched to the fourth state to separate the patching device and the feeding device, and the patching device is released and clung to the well leak in the second state, thereby sealing the well leakage. The oil well plugging process is simplified, and the construction efficiency of sealing the well leakage is improved.