A foreign object detection method, applied to a foreign object detection circuit in a foreign object detection apparatus , wherein the foreign object detection apparatus is applied to a wireless charging system, the foreign object detection apparatus further comprises a coil array , the coil array comprises at least one coil group, each coil group comprises four detection coils separately wound into a rectangle, the detection coils in the coil array are arranged in a matrix with even quantities of rows and columns, four detection coils in the coil array whose locations are symmetrical to each other are located in one coil group, and each detection coil is electrically connected to the foreign object detection circuit ; and characterized in that the method comprises: • obtaining an induction signal generated by each detection coil in each coil group; • determining an abnormal-value threshold of each coil group based on induction signals that are of each coil group and that are obtained in a first time period, wherein the first time period is a preset time period after the induction signals start to be obtained, wherein the abnormal-value threshold is dynamically determined based on the obtained induction signals, and wherein the determining of the abnormal-value threshold of each coil group is performed by using an interquartile range method based on signal values of the induction signals that are of each coil group and that are obtained in the first time period; and • detecting, based on the abnormal-value threshold and the induction signals of each coil group, whether there is a foreign object in a detection region corresponding to the coil array , wherein hereby for each detection coil of each coil group, the respective signal value of the obtained induction signal of the detection coil is compared with the abnormal-value threshold, to determine whether the induction signal of the respective detection coil is abnormal, and further to determine whether there is a foreign object in the detection region corresponding to the respective detection coil . • obtaining an induction signal generated by each detection coil in each coil group; • determining an abnormal-value threshold of each coil group based on induction signals that are of each coil group and that are obtained in a first time period, wherein the first time period is a preset time period after the induction signals start to be obtained, wherein the abnormal-value threshold is dynamically determined based on the obtained induction signals, and wherein the determining of the abnormal-value threshold of each coil group is performed by using an interquartile range method based on signal values of the induction signals that are of each coil group and that are obtained in the first time period; and • detecting, based on the abnormal-value threshold and the induction signals of each coil group, whether there is a foreign object in a detection region corresponding to the coil array , wherein hereby for each detection coil of each coil group, the respective signal value of the obtained induction signal of the detection coil is compared with the abnormal-value threshold, to determine whether the induction signal of the respective detection coil is abnormal, and further to determine whether there is a foreign object in the detection region corresponding to the respective detection coil . <EOS>