Based on the novel LTCC porcelain substrate formed through the low-temperature sintering of multi-layer green porcelain chips, the work aims to design a microchannel heat sink based on the structure of metal micropillar array to improve liquid cooling and heat dissipation performance of T/R modules and form a heat dissipation network structure of heat source, gradient interface layer, embedded micropillar array and liquid cooling channel to solve the problem of efficient thermal control of high-density chip arrays in T/R modules. The step-by-step finite element analysis method was used to simulate the heat and mass transfer process. The parameter controlled variable method was used to study the size of metal micropillar array and the effect of gradient interface layer on heat dissipation performance. The size of micropillar array structure and the gradient interface layer coating structure were optimized. The micropillar array structure optimized based on the theory of multiple heat sources heat dissipation network could reduce the maximum temperature of the interface heat source of liquid cooled microchannel from 126.96 ℃ to 58.89 ℃. The size parameters of the micropillar array structure based on the neat arrangement strategy were reduced to 52.478 ℃, a decrease of 10.88%. The temperature rise of gradient interface layer of the metal thermal conductive micropillar array silver copper alloy decreased to 53.211 ℃, the thermal strain decreased by 1.3%, and the thermal stress decreased by 3.7%. Through the optimization design and analysis of the multiple heat sources dissipation network structure, the microchannel heat dissipation network capability of metal thermal conductive micropillar array has been greatly improved, and the heat exchange performance of the T/R modules is better.