we demonstrate a high-resolution MIR dual-comb interferometer (DCI) system by using spectral interleaving. By generating electro-optic frequency combs (EOFCs) at 1550 nm via a dual-drive Mach-Zehnder modulator (DD-MZM) and employing injection locking to create a linearly swept lightwave spanning 18 GHz, we achieve gapless spectral interleaving. This swept lightwave serves as the seed for dual EOFCs with a 1 MHz repetition rate difference, which are subsequently converted to the MIR region (3.3 μm) via difference frequency generation (DFG). Experiment results demonstrate a dual-comb spectrum spanning 486 GHz with 100 MHz resolution, validated by direct detection and demodulation.