Systems and methods for liquid detection are disclosed. An illustrative method for liquid detection herein may include implementing CT imaging and XRD imaging on one or more liquid planes of liquid contained in a container at once by rotating the container so that X-rays from a same radiation source scan a whole area of each of the one or more liquid planes, and generating a substance identification result for the liquid contained in the container based on a CT image and a XRD image, wherein the CT imaging and the XRD imaging are implemented on a same liquid plane or different liquid planes. Consistent with various aspects and features, implementations may identify substances contained in the liquid more quickly and accurately.