The invention discloses a preparation method of tris(2-hydroxycyclohexyl) isocyanuric acid triacrylate. The preparation method comprises the steps of adding tris(2-hydroxycyclohexyl) isocyanuric acid, acrylic acid, a solvent, a catalyst, a first polymerization inhibitor and an antioxygen in a reactor, and uniformly mixing to obtain a reaction system; keeping the temperature of the reaction system at 90 to 150 DEG C, and pumping air into the reaction system to enable the reaction system to back flow to a reaction endpoint at constant temperature under normal pressure, so as to obtain a reaction product; sequentially washing the reaction product by water, alkali and salt, then standing for layering, and taking an upper layer to obtain an organic phase; adding the organic phase into a second polymerization inhibitor, performing reduced pressure distillation to remove the solvent in the organic phase, and performing pressure filtration on the organic phase to obtain the tris(2-hydroxycyclohexyl) isocyanuric acid triacrylate. The curing speed is fast, the mechanical performance is good, the shrinking percentage is low, the thermal stability and outdoor weather ability are excellent, the preparation steps are simple, and the cost is relatively low; an esterification reaction only needs 4 to 8h.