This work investigates the inverse interior scattering problem for quantum Bunimovich billiards subject to small boundary perturbations. We consider a billiard whose boundary is a piecewise C2 perturbation of the original domain. An incident field is generated from the center of each perturbed circular arc, and the resulting scattered field is measured on an auxiliary arc. By synthesizing the transformed field expansion method with Fourier analysis and mathematical induction, we develop a procedure to reconstruct the perturbation’s shape. We establish that, when the billiard boundary and the auxiliary arc are sufficiently close, the perturbation is uniquely determined by the imaginary part of the total field. Furthermore, we derive an explicit reconstruction formula involving a discrete Laplace transform, which demonstrates the efficacy of our method.