The invention discloses a pipeline leakage risk assessment method in a comprehensive pipe gallery. The method comprises the following steps: determining a possibility factor of leakage risk occurrenceand an influence factor after the leakage risk occurrence; performing hierarchical division on the risk occurrence possibility and the influence after risk shadow occurrence, and respectively constructing a hierarchical structure 1 of the risk occurrence possibility and a hierarchical structure 2 of the risk influence degree; respectively calculating the comprehensive weight of the possibility factor to the risk possibility L and the comprehensive weight of the influence degree factor to the risk influence degree S by adopting an analytic hierarchy process; respectively calculating a risk possibility L and a risk influence degree S; and performing leakage risk assessment by using the risk possibility and the risk influence degree. The leakage risk mechanism is analyzed, the possibility factor of leakage risk occurrence and the influence degree factor after occurrence are analyzed, basic data needed by the established leakage risk assessment method are easy to obtain, the compatibilitywith an existing pipe gallery safe operation monitoring system is high, and the method is suitable for practical engineering application.