Abstract: The crack damage of underground structure is an important factor affecting its safety status.In order to identify the safety status of traffic underground structure,based on the nondestructive testing information,by using the new intelligent optimization algorithm,Harris Hawks optimization (HHO) algorithm,and combing with the extended finite element method (XFEM) technology,a new HHO-XFEM method for reverse identification of underground structural cracks is proposed.The identification of structural crack under static and dynamic conditions are all studied.The results show that for static condition,the relative errors of crack length and dip angle are 2.5% and 3.4% respectively,and for dynamic condition,those errors are 6.9% and 3.0% respectively.Therefore,the inversion identification effect of the new method is suitable.