In this paper, a novel methodology for delamination profile diagnosis is proposed. First, the general inverse heat conduction problem (IHCP) is formulated and the corresponding adjoint problem derivation is presented. Following this, the conjugate gradient method with bound constraints is discussed and an one-dimensional numerical example is given to show the general procedures. Next, the heat conduction for two delaminated composite coupons is simulated using the commercial software ABAQUS. The extracted temperature history on the top and bottom surfaces is given as the available measurements in the delamination damage diagnosis framework. The detected results are compared with the ground truth to validate the feasibility of the proposed method. Finally, some conclusions and future work are drawn based on the current study.