The FDK algorithm is one of the most widely used algorithms for cone-beam CT reconstruction in circular trajectory due to its simplicity of implementation and computational efficiency. However, the images reconstructed by the FDK algorithm based on real projection data may be blurred without electronic correction and geometric calibration, and are often plagued by deleterious ring artifacts and shading artifacts. We compared the images reconstructed with and without detector correction based on computer experiment of the real biological object. The experimental simulation shows that these algorithms are effective in reducing the ring artifact without compromising the image resolution, and produce satisfactory results.