The invention discloses a deep foundation pit risk assessment method based on data fusion analysis. A foundation pit engineering three-dimensional digital model constructed according to a computer aided technology can completely record and vividly display all pieces of information of foundation pit construction and can automatically generate a construction log and a monitoring report, so that a constructor or a technicist can execute operation conveniently, and the work for recording complicated construction information of foundation pit engineering is eliminated. By a finite element analysis technology and the conventional risk assessment method for static assessment, single-monitoring-item dynamic assessment and multi-monitoring-item relevance assessment, the shortcoming of fuzzy judgment of the conventional risk assessment method is overcome; through a large amount of data fusion, a series of risk sources in an engineering progress process can be comprehensively judged, and a targeted strategy is supplied; and the intelligence degree is extremely high. According to the method, a learning mode can be adopted; and a risk judgment rule is added or corrected, so that the risk assessment accuracy can be continuously completed.