The invention discloses a method for acquiring an annular dark field image under a transmission electron microscope. The method comprises the following steps: firstly, selecting a zone which is required for image shooting, and collecting polycrystalline electron diffraction rings; secondly, selecting a diffraction ring which requires to acquire the annular dark field image, and carrying out continuous dark field image collection on a semi ring of the diffraction ring by using an objective aperture of the transmission electron microscope; finally, overlaying all collected dark field images to one picture by using software, thus acquiring the annular dark field image. The method disclosed by the invention has the advantages that the operation is simple, the cost is low, and implementation is easy.