City Safety is one of the most important issues facing humanity today. In the last century, given the frequency and intensity of earthquakes, globally as well as in China, more attention was paid to earthquake and disaster prevention approaches. China is one of the most affected countries in the world concerning earthquakes, so Chinese people and urban planners have intensified efforts of mitigating its disastrous effects. Therefore, establishing and improving continual and effective urban disaster prevention public space played an important role in preparations for a disaster. Lessons from the Great Tokyo Earthquake in Japan, the Great Tangshan earthquake in China etc. show that the city parks and green space played an important role of refugee disaster evacuation and preventing the spread of after-shock fire. In this thesis, I introduce a new design concept - earthquake disaster relief corridor - as a tool for disaster mitigation by open public space design. Literature from European and Japanese experience in disaster mitigation is used to gain experience of defense, evacuation of disaster victims and disaster recovery by reconstruction. The aim of thesis was thus to use the urban disaster prevention approach to formulate a design proposal for the Yucheng District, the main city area of Ya’an, with the goal of creating an effective emergency shelter system and a continual relief corridor. To address the aim, there are two research questions in this article: (1) How can a relief zone contribute to disaster mitigation? (2) How can a relief zone be designed in the case of Ya’an, Sichuan, China? As a new idea of urban public space design, urban earthquake disaster relief corridor will go through the overall city, generally start and end by rivers or mountains. In the normal days, the disaster prevention public spaces are entertainment, leisure and fitness places for citizens. When earthquake happens, their disaster prevention function will start immediately and become important urban disasters barriers. The relief corridor can also prevent the fire spread, evacuate refuge people, and become the home of disaster reconstruction. Therefore, no matter from the view of urban disaster prevention, or the improvement of the urban ecological environment, even beautify the urban environment, the disaster prevention open public space relief corridor will be an essential urban infrastructure. It will improve the city's service function and provide security to the citizens. This paper will assess the actual situation of China, learning from extensive experience mainly in America and Japan, starting from the research of earthquake disaster and earthquake disaster evacuation, then reviewing the disaster prevention park systems in Western countries and Japan, learning the disaster prevention park system, analyzing spatial cognition and human behavior in disaster evacuation. In the final part, the urban earthquake disaster relief corridor design proposal of Yucheng district, Ya’an, which is a seismic city, will focus on the aspects of efficiency, safety, ecology and so on. The relief urban planning makes a close connection between relief zone and urban construction elements, such as green space, city roads, buildings, illuminations and so on. At last, two different relief corridor types are established in Yucheng District, this thesis make a analysis about how the relief corridors work in disaster mitigation.