Winding structure of metal foreign matter detection coil for electromagnetic induction, method and system

The invention discloses an winding structure of a metal foreign matter detection coil for electromagnetic induction, a method and a system. The winding structure comprises a first-stage coil matrix, wherein the first-stage coil matrix comprises a first detection coil group, the first detection coil group comprises four first detection coils, the four first detection coils are distributed in a shape like a Chinese character tian and are sequentially connected end to end to form a coil, and the winding directions of every two adjacent first detection coils are opposite. The detection method comprises the following steps: detecting an induced voltage U1 of the first-stage detection coil matrix, and if U1 exceeds a preset threshold U01, judging that there is a metal foreign matter; if the U1 does not exceed the preset threshold U01, further detecting the induced voltage U2 of a second-stage detection coil matrix, and if the U2 exceeds a preset threshold U02, judging that a metal foreign matter exists; and if the