The application relates to the technical field of composite materials, and discloses a preparation method of a multilayer composite core body, which comprises the following steps: pretreatment, spraying treatment, core
composite material preparation, compounding and curing forming; the surface of a
fiber base layer is chemically modified through functional pretreatment, the wettability and reactivity of the
fiber surface are improved, the different
fiber layers with different functional characteristics can be more closely and stably combined, and therefore the integrity, reliability and durability of the multilayer composite core body structure are enhanced; through spraying treatment, functional particles are uniformly loaded on the surface of the fiber base layer in the form of a stable dispersion liquid; the functional particles have good compatibility and bonding force with the fiber base and the interlayer
composite material after being treated and surface-modified in a specific manner, the core body is endowed with specific surface functions, the
interface bonding between the fiber and the base is enhanced, and the functionality, uniformity and structural strength of the core body are improved.