Mirrored interferometric aperture synthesis (IAS) (MIAS) is a novel interferometry which has the potential to reduce system complexity compared with that of conventional IAS. Array configuration design plays a major role in imaging. As the concept of MIAS was proposed just a few years ago, the problem of array configuration design has not been solved yet. In this letter, the principles of array configuration design of 1-D MIAS are proposed, and the corresponding optimization model is established and refined. The optimal array configurations are presented through simulated annealing method and show that 1-D MIAS can achieve almost twice as much of spatial resolution as 1-D IAS with the same array size.