The invention discloses a dam body damage explosive quantity estimation method based on underwater explosion test measurement results. The dam body damage explosive quantity estimation method includesthe steps: acquiring the critical value of explosion impact load peak pressure applied to a dam body under critical damage conditions according to dam parameter simulation; building an underwater explosion test device based on a detonator and explosives, performing series explosion tests under the condition of determined explosive load, charging submerged depth and inflation pressure in a container, measuring the impact wave peak value of underwater explosion and acquiring the relationship between the explosive load and the underwater impact peak pressure by fitting; finally, estimating dam body damage explosive quantity. The dam body damage explosive quantity estimation method has the advantages of simplicity, convenience and low cost.