The invention belongs to the field of design, preparation and application of novel materials and relates to a 3D printing aluminum honeycomb structure based on a composite phase change material. The invention also discloses a preparation method. The 3D printing aluminum honeycomb structure comprises a honeycomb shell by 3D printing, the honeycomb shell is formed by sequentially lying and extendinghollow hexagonal-prism-shaped single cavities, the inner wall of each single cavity is provided with stabs, the stabs are distributed on the inner wall of each single cavity and incline towards the same bottom surface direction, and each single cavity is filled with a composite phase change material. The main purpose of the invention is to continuously and stably dissipate heat of a power batteryof an electric vehicle, thereby ensuring good use performance and endurance mileage of the electric vehicle. The honeycomb structure can be widely applied to various occasions needing to be cooled, such as motors, aircrafts and submarines which need heat management.