This application relates to the field of wireless charging, and provides a coil assembly, an electronic device, and a wireless charger. The coil assembly includes a first coil winding, a second coil winding, and a circuit board. The first coil winding includes a plurality of first wire groups, and has a first lead-out end connected to an external circuit. The second coil winding includes a plurality of second wire groups, and has a second lead-out end connected to the external circuit. The second coil winding is stacked with the first coil winding. A plurality of first terminals and a plurality of second terminals are disposed on the circuit board. Each first terminal is connected to each second terminal by using a cable. In a plurality of cables used to connect the plurality of first terminals and the plurality of second terminals, at least two cables are changed to different line layers in a cross region through first vias to be disposed in a crossed manner. A first connection end of each first wire group is connected to a second connection end of each second wire group by the first terminal and the second terminal. The coil windings of the coil assembly in this application generate low heat, and transmission efficiency of electric energy is high.