In order to make a better understanding of the different assessment methods applied in the urban physical protection system, and a comprehensive analysis and generalization of its quo status and development tendency, this paper used the main thesis data banks such as Web of Science, Science Direct, Engineering Village, CNKI, etc. to have searched more than 200 papers and books about the risk assessment researches to urban physical protection system between 2008 and 2018. Based on the search results, we classified six types of risk assessment methods commonly used, and analyzed the features and effects of each type so that the application values and prospect of the risk assessment methods in urban safety area have been explored. The results show that different assessment methods may have their own advantages in different urban areas, and that the choice of certain methods mainly depends on specific scenes and areas with a necessary adjustment, and more importantly a comprehensive and advanced assessment method/s may be preferably chosen to meet the needs of modern urban construction so as to make different kinds of risk assessment and provide a solid safety for a modern city in the physical protection system.