A heating assembly is provided. The heating assembly includes: a substrate; at least one heat generating element, the heat generating element being formed on the substrate; at least two electrical contacts, the electrical contacts being formed on the substrate, and the electric contacts being electrically connected to the heat generating element; and at least one heat insulation structure, the heat insulation structure being formed on the substrate and located between the heat generating element and the electrical contacts. The present invention further relates to an atomizing core and an aerosol generating device. The heating assembly, the atomizing core, and the aerosol generating device provided can limit heat loss of a hot area and avoid the extremely high temperature of a cold area, thereby improving the atomization efficiency and reducing heat resistance requirements of the heating assembly, the atomizing core, and the aerosol generating device for the electric contacts.