An electric motor structure, comprising: at least two magnet sets disposed oppositely at a distance, where each magnet set comprises a magnet (51, 55) having poles arranged perpendicular to the magnet (51, 55) 's movement, the magnets (51, 55) in a same magnet set are stacked and have poles (N, S) of reversed polarities on a same side, and opposing magnets (51, 55) from neighbouring magnet sets have facing poles (N, S) of a same polarity; at least one coil assembly disposed between two neighbouring magnet sets, where the magnet sets and the at least one coil assembly conduct a relative movement, the at least one coil assembly is axially parallel to an alignment direction between the facing poles poles (N, S) of opposing magnets (51, 55), the at least one coil assembly comprises a magnetizer wrapped in a winding, and a front yoke and a back yoke extended from two ends of the magnetizer towards opposite directions, the front yoke interacts first with a magnet (51, 55) in the relative movement, the back yoke interacts later with a magnet (51, 55), a specific distance (a) is between the front and back yokes (611, 612), and a front detection element and a back detection element are respectively provided on the front and back yokes (611, 612); and a detection switch circuit disposed between the magnet sets and the at least one coil assembly, where the detection switch circuit comprises at least a negative indicator or at least a positive indicator, each disposed at a pole (N, S) on a magnet (51, 55) that interacts earlier with the front yoke of the at least one coil assembly in the relative movement, the negative indicator is disposed at an N pole of a magnet (51, 55) having the N pole facing the at least one coil assembly, the positive indicator is disposed at an S pole of a magnet (51, 55) having the S pole facing the at least one coil assembly, the detection switch circuit further comprising at least one break indicator, the break indicator being disposed at a pole (N, S) on a magnet (51, 55) that interacts later with the back yoke of the at least one coil assembly in the relative movement; wherein, when the front detection element detects the negative indicator or the positive indicator, a positive or negative power supply is applied to the at least one coil assembly; and, when the back detection element detects the break indicator, the positive or negative power supply to the at least one coil assembly is cut off, wherein the front and back yokes (611, 612) are extended at an angle greater than right angle relative to the magnetizer so as to effectively increase the distance (a). at least two magnet sets disposed oppositely at a distance, where each magnet set comprises a magnet (51, 55) having poles arranged perpendicular to the magnet (51, 55) 's movement, the magnets (51, 55) in a same magnet set are stacked and have poles (N, S) of reversed polarities on a same side, and opposing magnets (51, 55) from neighbouring magnet sets have facing poles (N, S) of a same polarity; at least one coil assembly disposed between two neighbouring magnet sets, where the magnet sets and the at least one coil assembly conduct a relative movement, the at least one coil assembly is axially parallel to an alignment direction between the facing poles poles (N, S) of opposing magnets (51, 55), the at least one coil assembly comprises a magnetizer wrapped in a winding, and a front yoke and a back yoke extended from two ends of the magnetizer towards opposite directions, the front yoke interacts first with a magnet (51, 55) in the relative movement, the back yoke interacts later with a magnet (51, 55), a specific distance (a) is between the front and back yokes (611, 612), and a front detection element and a back detection element are respectively provided on the front and back yokes (611, 612); and a detection switch circuit disposed between the magnet sets and the at least one coil assembly, where the detection switch circuit comprises at least a negative indicator or at least a positive indicator, each disposed at a pole (N, S) on a magnet (51, 55) that interacts earlier with the front yoke of the at least one coil assembly in the relative movement, the negative indicator is disposed at an N pole of a magnet (51, 55) having the N pole facing the at least one coil assembly, the positive indicator is disposed at an S pole of a magnet (51, 55) having the S pole facing the at least one coil assembly, the detection switch circuit further comprising at least one break indicator, the break indicator being disposed at a pole (N, S) on a magnet (51, 55) that interacts later with the back yoke of the at least one coil assembly in the relative movement; wherein, when the front detection element detects the negative indicator or the positive indicator, a positive or negative power supply is applied to the at least one coil assembly; and, when the back detection element detects the break indicator, the positive or negative power supply to the at least one coil assembly is cut off, wherein the front and back yokes (611, 612) are extended at an angle greater than right angle relative to the magnetizer so as to effectively increase the distance (a).