A coil module, comprising: an insulation layer, a first planar coil winding, and a second planar coil winding, wherein the first planar coil winding is on one side of the insulation layer, the second planar coil winding is on the other side of the insulation layer, and the first planar coil winding and the second planar coil winding each comprise a plurality of turns of coils; at least one turn of coil of the first planar coil winding comprises a first portion, a second portion, and a first connection part; the first portion is provided with a first cutting opening that extends along a coil extending direction, the first portion comprises a first outer side part and a first inner side part that are separated by the first cutting opening; the second portion is provided with a second cutting opening that extends along the coil extending direction, the second portion comprises a second outer side part and a second inner side part that are separated by the second cutting opening; and the first connection part is disposed between and in electrical contact with the first outer side part and the second inner side part; at least one turn of coil of the second planar coil winding comprises a third portion, a fourth portion, and a second connection part; the third portion is provided with a third cutting opening that extends along the coil extending direction, the third portion comprises a third outer side part and a third inner side part that are separated by the third cutting opening; the fourth portion is provided with a fourth cutting opening that extends along the coil extending direction, the fourth portion comprises a fourth outer side part and a fourth inner side part that are separated by the fourth cutting opening; and the second connection part is disposed between and in electrical contact with the third inner side part and the fourth outer side part, wherein the coil extending direction is the winding direction of the coil; and there is an overlap between a projection of the first connection part on a plane of the insulation layer and a projection of the second connection part on the plane of the insulation layer, the first outer side part and the third outer side part are connected in parallel, the first inner side part and the third inner side part are connected in parallel, the second outer side part and the fourth outer side part are connected in parallel, and the second inner side part and the fourth inner side part are connected in parallel. the first planar coil winding is on one side of the insulation layer, the second planar coil winding is on the other side of the insulation layer, and the first planar coil winding and the second planar coil winding each comprise a plurality of turns of coils; at least one turn of coil of the first planar coil winding comprises a first portion, a second portion, and a first connection part; the first portion is provided with a first cutting opening that extends along a coil extending direction, the first portion comprises a first outer side part and a first inner side part that are separated by the first cutting opening; the second portion is provided with a second cutting opening that extends along the coil extending direction, the second portion comprises a second outer side part and a second inner side part that are separated by the second cutting opening; and the first connection part is disposed between and in electrical contact with the first outer side part and the second inner side part; at least one turn of coil of the second planar coil winding comprises a third portion, a fourth portion, and a second connection part; the third portion is provided with a third cutting opening that extends along the coil extending direction, the third portion comprises a third outer side part and a third inner side part that are separated by the third cutting opening; the fourth portion is provided with a fourth cutting opening that extends along the coil extending direction, the fourth portion comprises a fourth outer side part and a fourth inner side part that are separated by the fourth cutting opening; and the second connection part is disposed between and in electrical contact with the third inner side part and the fourth outer side part, wherein the coil extending direction is the winding direction of the coil; and there is an overlap between a projection of the first connection part on a plane of the insulation layer and a projection of the second connection part on the plane of the insulation layer, the first outer side part and the third outer side part are connected in parallel, the first inner side part and the third inner side part are connected in parallel, the second outer side part and the fourth outer side part are connected in parallel, and the second inner side part and the fourth inner side part are connected in parallel.