Abstract: An important bottleneck in spatial spectrum estimation theory is array errors. A new error self-calibration method is presented on the basis of active error calibration and online self-calibration theories. An algorithm combining Direction Of Arrival (DOA) estimation and array complex gain error calibration is developed using an auxiliary source without accurate spatial location information and numerical optimization calculation; the error calibration parameters can be used in the following spatial spectrum estimation. The method has a higher veracity than the active correction algorithm and is an offline calculation procedure, having the advantage of small computation amount, similar to the online self-calibration method, and avoiding accurate spatial location information in classical active calibration method.