A method of manufacturing a heat dissipation sheet including preparing a preliminary sheet including a matrix-forming component, a crosslinking agent, and a heat dissipation filler, and crosslinking the matrix-forming component included in the preliminary sheet and thus obtaining a heat dissipation sheet. The heat dissipation sheet manufactured has remarkably excellent heat dissipation properties because it contains a high content of heat dissipation filler. Due to the material properties of the matrix-forming component and the crosslinking of the matrix-forming component and the resulting matrix formation, the occurrence of cracking, shrinkage, pore formation, thickness change, and the like is minimized or prevented, and excellent flexibility can be attained. Moreover, since processability is improved through processes such as cooling when manufacturing the heat dissipation sheet, productivity is excellent, and the sheet can be suitable for mass production.