In order to ensure the safety of shield construction, the risk assessment in shield construction was carried out based on entropy theory. According to the actual situation of the Shenyang Metro Line engineering, risk assessment system in shield construction was proposed,which contains 4 one-class indexes: shield construction equipment, engineering geological and hydro-geological, environmental impact and shield operation,and one-class indexes contained 22 two-class indexes, each index weight was analyzed, and shield construction risk assessment model was established based on the entropy theory. Through the analysis, the overall risk in the process is regarded as acceptable risk, need close attention. Based on regulate operation as well as strict control measures, there will be no risk in the construction process.