The ferromagnetic boundary coupling effect is an important factor affecting the coil uniformity, and the non-moment coils (NMCs) design method is often used to solve this problem. This paper proposes a non-moment planar coils (NMPCs) design method based on bat algorithm (BA) and self-shielding method, which can inhibit the coupling effect between the coils and the high magnetic permeability shielding layer, and improve the uniformity of the target region. We design Bx and Bz NMPCs, and use finite element software to simulate and calculate, verifying the performance of the method. Compared with ordinary planar coils (OPCs) in the shielding layer, the target region uniformity of this method has been significantly improved, Bx and Bz have increased by a factor of 17.28 and 10.57 respectively. This method can provide a new coil design idea for precise ultra-weak magnetic testing.