In this paper, a slotted-type MEMS capacitive pressure sensor is designed and simulated using ANSYS and MEMSPro software. The sensor consists of stacked glass and gold layers that act as the backplate electrode, while the diaphragm forms the top electrode in a parallel-plate capacitive configuration. The air gap and capacitance vary as the diaphragm deflects under applied pressure, allowing the change in capacitance to be used for sensitivity calculation. The diaphragm was analyzed under pressures ranging from 0 to 4000 kPa using aluminum, titanium alloy, and magnesium alloy as materials. Simulation results show that aluminum exhibits the highest total deformation of 18.93 µm and the largest capacitance change of 1.07 × 100 pF, corresponding to a sensitivity of 2.96 × 10−1 pF/MPa, which is approximately 35% higher than titanium alloy and 55% higher than magnesium alloy. Titanium alloy shows moderate performance, while magnesium alloy demonstrates the lowest deformation and sensitivity. The fabrication process of the pressure sensor is also simulated, and a 3D structural model is generated using MEMSPro. Overall, aluminum is identified as the most effective diaphragm material due to its superior deflection, capacitance variation, and sensitivity performance.