The size of heat transfer enhancement equipment has an important effect on the efficiency of heat exchangers and Heat exchanger network (HEN) structure. A novel mixed integer nonlinear programming (MINLP) model of HEN synthesis considering the types and size of enhancement equipment is proposed, solved by hybrid genetic algorithm/simulated annealing algorithm (GA/SA). In this model, the type and size of the enhancement equipment are set as the integers and continuous variables, respectively, and the enhanced equipment costs and operating costs associated with pressure drop are added in the total annual cost (TAC). The MINLP mathematical model of simultaneous synthesis is established by the combining of heat transfer coefficient and pressure drop models of heat exchangers for enhancement equipment and the HEN synthesis model based on the stage-wise superstructure. The new method has distinctive advantages over existing design methods, as the new MINLP model can effectively achieve simultaneous optimization of the types and size of enhancement equipment and HEN. Finally, the feasibility and effectiveness of the proposed model are proved through concrete case analysis.