Cycloaliphatic epoxy resins, due to the presence of saturated six-carbon rings with a flexible space shape in the main structure, have the ability to be used in the manufacture of high-performance composite parts and have received the attention of composite industries. Researchers have succeeded in synthesizing this resin in various ways and have achieved acceptable chemical, physical, mechanical, thermal and electrical properties, but they have always faced problems in the synthesis method, production process and raw materials, and this limits the use of the above resins. With the aim of improving the synthesis methods and using commercial monomers, this research tries to take a step towards the application of cycloaliphatic epoxy resins. For this purpose, the synthesis and characterize tri-functional cycloaliphatic epoxy resin of diglycidyl-4,5-epoxy-cyclohexane-1,2-dicarboxylate (ECDAD) using raw material of tetrahydrophthalic anhydride was performed by four different methods and the optimal route was presented. For the synthesis of cycloaliphatic epoxy resin, the processes of epoxidation of carboxylic acid with epichlorohydrin, allylation of carboxylic acid with allyl bromide, direct epoxidation of double bond of branches and double bond of cycloalkene with compounds of 3-chloroperoxybenzoic acid (m-CPBA) and trichloroisocyanuric acid (TCCA) were used and different methods were compared. Generally, the epoxidation of alkenes has challenges such as low purity, long reaction time, high cost, and difficult separation, therefore, in this article, a suitable and practical method for the epoxidation of alkenes using TCCA was presented. In this research, two epoxy resins (bi-functional and tri-functional) were synthesized and their synthesis steps were investigated and confirmed by FT-IR, 1H-NMR, 13C-NMR analysis and the measurement of the epoxy equivalent weight (EEW). The EEW of the synthesized resins of bi- and tri-functional was 152 and 108 (g/eq), respectively, and their curing process was evaluated and confirmed using DSC analysis.