Despite appropriate design of beams under bending and shear, the deflection of long steel beams usually exceeds the allowable range, and therefore the structural designers encounter challenges in this regard. Considering significant features of the cables, namely, low weight, small cross section, and high tensile strength, they are used in this research so as to control the deflection of beams, rather than increasing their heights, and obtain acceptable responses. In this study, for the first time, theoretical relations are developed to calculate the increase in pre-tensioning force of cables under external loading based on the method of least work as well as the deflection of of steel beam with different support conditions and cable patterns based on the virtual work method. To verify the theoretical relations, the steel beam is modeled in the finite element ABAQUS software. The obtained results show that the theoretical relations can appropriately predict the deflection of beam with different support conditions and cable patterns. In this study, simply supported as well as fixed supported beams are pre-stressed with V-shaped and modified V-shaped patterns of the cable. According to the obtained results, the modified V-shaped pattern of the cable is more efficient than V-shaped pattern one.