Abstract: This study analyzes critical issues in the disaster prevention design of urban three-dimensional space： 1） the lack of practical spatial planning for disaster prevention guided by safety assessment techniques； 2） the inability of current design strategies to address issues posed by different spaces within special urban areas； 3） the absence of a comprehensive qualitative-quantitative approach for the “normal-to-emergency” transition design of municipal facilities. In response， typical disaster scenarios for urban three-dimensional space are proposed. By examining relevant domestic and international cases， a disaster prevention design framework is established， encompassing three aspects： determination of planning layout， disaster prevention spaces， and disaster prevention facilities. Based on the scenario of flood backflow in underground spaces， a full-cycle design strategy of “Avoid-Withstand-Absorb” is proposed. For fire， explosion， and earthquake scenarios in multi-level street networks， a strategy for rationalizing three-dimensional evacuation systems is presented. For emergency evacuation in ultra-high spaces， the introduction of upper-level buffer zones is suggested to enhance evacuation efficiency.