Abstarct: Diaphragm pumps are positive displacement pumps which have many applications in the petrochemical, oil, gas and so on. diaphragm pumps examples can be cited Infusion pumps which due to the good resistance against chemical fluids are highly regarded in the gas industry. Since the diaphragm pumps are composed of various mechanical parts, which some of them, like the diaphragm are in direct contact with the fluid, many different causes mechanical damage reports from some consumer companies such as gas company has announced. for this purpose, find a model similar to the actual model is very useful. one of these pumps design and manufacturing methods is using commercial codes for simulation rather sophisticated and expensive laboratory methods. since the fluid in the pump is transmitted by a diaphragm motion, concept called the fluid structure interaction is defined. due to problems related to simulations of fluid structure interaction, animated network simulation and geometry of the pumps, limited efforts have been done in the past for numerical analysis of these pumps. today, with significant progress performed in the development of computational systems and commercial codes, a good platform for the simulation of such problems is created. there are several methods for simulating fluid structure interaction problems which due to the small deformation of the diaphragm and flow fields in front of other aspects of the model pump, one way method is selected for this simulation. in order to reduce the size of the pump dimensional model calculations, this pump is simulated using ANSYS CFX commercial code. in this study, we generated a model that could well show some parameters of this type of pump that future studies with a reduced construction costs, a more efficient model can be produced. one of the results of presented method, is introducing one way fluid structure interaction method as a suitable modeling method. the other results that can be mentioned is the study on the velocity and pressure fields, the effect of functional parameters such as engine speed and displacement diaphragm pump on stream and other outcomes that are fully addressed in a season. in order to validate the model the boundary conditions of a real sample fluid injection pump odorant in city gas company is Ptrvsavyz is used that after comparing the amount of output in terms of displacement diaphragm with the information contained in the pump catalog, in the worst case, error rate 10% and an average error is about 5%.