Aiming at accidents caused by closing the breaker with grounding wires of double circuit lines, a method for detecting temporary grounding wires is proposed in this paper. A reformed grounding wire is hooked at the detection position, phase of a reference inductive current and current in detection grounding wire will be compared to judge whether there is a temporary grounding wire or not. The simulation software ATPDraw is used to verify the reliability and practicality of the method. This method takes the coupling problem between double lines into account. It is simple, low cost, reliable, sensitive, and can avoid accidents caused by closing the breaker with ground wires technically.