Quantitative density reconstruction of an object in detonation process using high-energy flash radiography is described.In order to obtain the path length of the object,the radiographic image of the object is corrected by an integrated nonlinear function that represents the nonlinear imaging process of the high-energy flash radiographic system.The function is measured from the image that is obtained from a pre-knowing sample,and the sample is structural similitude with the object.The path length is reconstructed by algebraic reconstruction technique with the rule of least error.Then the density distribution of the object is obtained form the result of reconstruction when the mass absorption coefficient is deducted.A series of density reconstructions of a static radiographic test object is obtained by the radiographic system,and the results show that the errors of the density reconstruction are approximated to 10%.