Compared with the traditional mechanical scanning mechanism, optical phase array has the advantages in scanning accuracy, speed and rotation inertia. Thus, it is considered as a potential solution for multiple targets positioning and three-dimensional imaging in wide view range. Since MEMS integrated photonics technology has been developed rapidly, silicon waveguide optical phase array attracts much attention for its application in panoramic imaging and lidar. A 16-units phase array device is introduced and designed in this article after the basic principle and mathematical model is indicated. And the thermal analysis is also realized while the temperature distribution is simulated. Based on this design, the main components such as grating coupler, MMI beam splitter and grating antenna are simulated and optimized with FDTD. After that, the practical device is fabricated with EBL and the test platform is also built for verifying the device performance. According to the test results, the scanning accuracy (1.2°), range (larger than ±30°) and speed (20 kHz) are derived, so that the full design process is verified.