In order to improve the sensitivity of weak pressure sensors, a pressure sensor with excellent performance was fabricated by using microstructure to produce piezo resistive effect. Three kinds of graphene pressure sensors with different structures were studied. The layout structure, process preparation and material characterization of graphene pressure sensors were designed and studied. Finally, the sensitivity of the three graphene pressure sensors with different structures was tested. The experimental results show that the graphene pressure sensor with network structure has high sensitivity, the sensitivity can reach 0.303 kPa-1 at low pressure (0-200 Pa), and the lowest pressure can be detected at 24.5 Pa. The graphene pressure sensor with network structure is a high performance pressure sensor that can sense weak pressure changes.