To address the contradiction between a small number of grid lobes and a narrow main lobe in the range dimension beampattern of conventional FDA-MIMO radar, a Cantor Multi-stage frequency offset FDA-MIMO(CMSEO FDA-MIMO) structure is introduced. Moreover, a combination of frequency offset and array element number configuration methods is proposed. We derived the relationship between the main lobe width and periodic range with frequency offset and fractal order. Furthermore, the frequency offset and array element order relation closed-form solutions for main lobe invariance and grid lobe reduction are derived. Simulation experiments demonstrate the effectiveness of the proposed method.