We have proposed and demonstrated the fabrication of fiber-optic Fabry-Perot interferometer (FPI)-based fiber-optic sensor by 3D printing technology with digital optical processing (DLP) for water pressure sensing application. The mirrors of FPI are provided by the end face of the fiber and the inner surface of the printed resin sensor head. By analyzing the characteristics of the sensor head prepared by 3D printer, the interference contrast is enhanced through the optical fiber end face with an eight degrees angle. The obtained pressure sensitivity is 536.9 nm/MPa. This method of fiber optic pressure sensor has the characteristics of simple manufacturing process, mass production and high sensitivity. Keywords: fiber-optic sensor, 3D printing technique, pressure sensor, Fabry-Perot cavity.