It aims to explore the design principle and direction of public facilities in urban public open space. Starting from the importance of public facilities in urban public open space, it analyzes the rest in people's life, entertainment and communication, the aspects of function, at the same time analyzes the problems in reality and insufficient, summarizes the design principle of the future, from the perspective of ecology, such as science, humanity, aesthetics to explore the direction of the urban public open space of the public facilities design, and then respectively into urban public facilities in the park design, commercial pedestrian street public facilities design two aspects to discuss the specific design strategy, explores the perfect combination of function and art, trying to find the best of the environment, balance. The relationship between urban public open space of public facilities design throughout the city cultural image, represents a city's mental outlook, some public facilities design in full range of design thinking and practice, to build a more dynamic city space, to better enhance urban grade.