A catching device for foreign matter in a blood vessel is composed of a micro guide wire A and a micro guide wire B. The micro guide wire A is magnetic, the micro guide wire B has ferromagnetism and is non-magnetic, and the catching device is formed by matching the micro guide wire A and the micro guide wire B. The invention further provides a catching method of the catching device. The method comprises the steps that firstly, the micro guide wire A penetrates through a clearance of the shifted foreign matter; then, the micro guide wire B penetrates through other clearances of the shifted foreign matter; then, the tail end of the micro guide wire A is used for attracting the tail end of the micro guide wire B, the two micro guide wires are rotated at the same time, and the shifted foreign matter is tightly wound and entangled; finally, the two micro guide wires are pulled out at the same time, and the foreign matter is pulled out of the blood vessel. The device and method are suitable for the situation that in endovascular intervention operations, spring rings and other operational materials shift and fall off to block the normal blood vessel, and the catching device catches the foreign matter firmly, easily, conveniently and safely, safe and good in operation stability, low in damage to the blood vessel, and suitable for micro blood vessels capable of being reached in all the interventional operations.