The invention relates to a risk analysis and risk evaluation method based on physical chemistry. The risk analysis and risk evaluation method based on the physical chemistry mainly solves the problem that risk analysis and risk evaluation methods close to process intrinsic safety are lacked at the early stage of projects in the prior art. According to the risk analysis and risk evaluation method based on the physical chemistry, an analytical method of the systematic physical chemistry is adopted, structures of substances are analyzed from the perspective of structural chemistry and substance risk recognition is carried out by the application of the structural chemistry; changes of a state function are calculated by means of a chemical thermodynamics method, and whether gain and loss of energy happen in a chemical reaction process is judged; the reaction mechanism, the reaction process, whether a reaction is easy to control and whether unexpected reactions can happen are analyzed through a chemical reaction kinetics method, and then risk recognition, risk analysis and risk evaluation are conducted on the basis of the analysis results. Safety protection measures needing to be adopted are put forward in the technical scheme, the problems are well solved, and the risk analysis and risk evaluation method based on the physical chemistry can be used for risk analysis and evaluation work at the early stage of the projects.