In millimeter-wave multiple-input-multiple-output(MIMO) array imaging, image reconstruction relies on point-by-point back propagation algorithm due to the irregular antenna arrangement. As a result, the reconstruction speed cannot meet the need of fast imaging. In order to solve this problem, a hierarchical “Coarse-To-Fine” reconstruction strategy is proposed. The fast coarse reconstruction based on phase compensation and the fine reconstruction based on back propagation are combined to process the MIMO holographic data. The millimeter wave imaging experiments by using orthogonal arrays and compact square arrays are simulated by Feldberechnung bei Korpern mit beliebiger Oberflache(FEKO), verifying the effectiveness of the proposed hierarchical reconstruction method.