This application relates to the technical field of electronic devices, and provides a core, a speaker module, and an electronic device, to balance thinning and audio performance of the device. The core includes a diaphragm assembly, a first voice coil set, a second voice coil set, and a magnetic circuit system. The first voice coil set and the second voice coil set are fastened to the diaphragm assembly. The magnetic circuit system includes a magnet assembly. The magnet assembly includes a first central magnet, a second central magnet, and a side magnet. A magnetization direction of the second central magnet is the same as a magnetization direction of the first central magnet. The core provided in embodiments of this application is configured to convert an audio electrical signal into sound.