Polymer matrix composites are a widely used category of composites whose properties are viscoelastic and highly dependent on temperature. One of the most important steps in the construction of polymer matrix composites is the curing process, which causes the creation of a network of transverse bonds. This process can increase the glass transition temperature and improve the mechanical properties. Epoxy, as a matrix, has desirable properties such as good thermal resistance, high tensile strength, and very good chemical resistance. However, epoxy has disadvantages, the most important of which are its brittleness after curing and inadequate impact resistance. In order to solve this problem, polyurethane, which is an elastic polymer, is used as a modifier to improve the mechanical properties, especially the hardening of epoxy. Compared to pure epoxy matrix, epoxy/polyurethane composites have better mechanical properties and thermodynamic performance. To achieve the best result for composites with epoxy matrix with low percentage of modifier and suitable natural properties, optimization of the manufacturing process is the essential factor that should be considered. In this article, the multi-objective optimization of manufacturing parameters in epoxy resins used in the manufacturing has been carried out. Experiments and optimization have been done by RSM/CCD method. The effect of three parameters of temperature, time and weight percentage of polyurethane on the yield strength and Young's modulus of epoxy/polyurethane composite has been investigated and according to this method, the most optimal values were selected for the maximizing of responses.