The invention provides a method and device for simulation distribution of underwater blasting shock relieve vents, and belongs to the field of underwater blasting engineering. According to the method and device, after a definite element analysis model is established and a corresponding simulation result is calculated through the initial distribution parameters, material models and state equations of blasting holes and the shock relieve vents, a new definite element analysis model is obtained each time when one of the initial distribution parameters of the shock relieve vents is changed, the optimal value of the changed distribution parameters of the shock relieve vents is obtained by comparing different simulation results, and the method and device have important promotion significance in improving underwater blasting construction efficiency, reducing construction cost and ensuring the safe use of adjacent buildings and structures and have a positive promotion effect on further compensating for and enriching the underwater blasting basic theory.