Preparation method of thermal interface material based on multi-component composite high-thermal-conductivity filler

A preparation method of a thermal interface material based on a multi-component composite high-thermal-conductivity filler relates to the technical field of a preparation method of a high-thermal-conductivity filler, and comprises the following steps: S1, activation pretreatment of a solid boron source; s2, pretreatment of the basic filler; s3, assembling and heat treatment of a reaction precursor; s4, growing, purifying and grading the boron nitride nano material; s5, performing thermal interface composite phase change material mother liquor slurry; and S6, continuous preparation of the thermal interface material. The fluid viscosity is controllable in the processing process, the overall heat-conducting property of the composite insulating thermal interface material is improved, the mechanical property limit in the prior art is broken through, a stable dispersion system is constructed, transmission of phonons among phase interfaces is facilitated, and the thermal conductivity of the composite insulating ther