Capillary pressure plays a crucial role in extracting oil from underground Reservoir. Simultaneous measurement of capillary pressure and electrical index of rock leads to the determination of connate water saturation, which plays an important role in calculating the amount of oil in situ. Since the study of the core in the laboratory is the only direct way to obtain the parameters of the reservoir, the laboratory results of the electrical resistance measurement are also used to calibrate the electrical resistance log. Another result of measuring capillary pressure and resistivity index is achieving the height of the transition area. Oil displacement modeling is also achieved by measuring capillary pressure in terms of different degrees of water saturation, which is used to determine the efficiency of immissible injection methods to increase oil recovery. The purpose of this study is to design a device to measure capillary pressure and electrical resistivity index in terms of degree of saturation. Designing such a device, which covers a wide range of laboratory operations, can lead to significant cost reductions because importing a foreign sample of this device is very costly. In this research, using the knowledge of petroleum engineering and the principles of mechanical and electrical design, a device for simultaneous measurement of capillary pressure and rock resistivity index is designed and an attempt is made to increase the capabilities of the device compared to its previous models. It Does the test more quickly and accurately.