The invention relates to a multi-azimuth-angle target direction sidelobe suppression method and device for an SAR image and aims to solve a problem of target information loss due to a method of suppressing a target sidelobe of the SAR image in the related art. The method includes acquiring a monovision complex image through the SAR; performing deramping treatment on the acquired monovision compleximage and obtaining a first image; performing fast Fourier transform on the first image along the height direction and acquiring a second image; determining a signal overlapping area in the height direction of a target main sidelobe in the second image; performing energy superposition on signals of the signal overlapping area along the height direction. By adopting the method provided by the invention, the target direction sidelobe can be suppressed effectively and SAR image quality can be improved.