The conceptual design of China fusion engineering test reactor (CFETR) is now ongoing. Its toroidal field magnets with a peak field of ∼15 T require a new conductor testing facility with higher background magnetic field to test and evaluate the performance of these conductors. As part of the study of CFETR, the facility named Super X (SUPERconducting eXperiment) is planning to be constructed at Institute Plasma and Physics, Chinese Academy of Sciences (ASIPP) and a conceptual design activity related is going on in parallel. The background magnetic field of the facility is generated by three concentric pairs of split coils with a bore of ∼600-mm diameter, inner coil (IC, peak field of 15.6 T), middle coil (MC, 13 T), and outer coil (OC, 10.5 T) in which IC and MC are connected in series with a nominal operating current of 7.9 kA, whereas OC operates at 13.5 kA. Each split pair coil is made of its own distinctive rectangular shaped cable-in-conduit conductor. The design and preliminary results of electromagnetic optimization and structural mechanical analysis for the background magnet system are presented.