A CT method and an apparatus for liquid safety-detection with a radiation source relate to a radiation imaging detecting technology field. The invention comprises using a radiation source, a detector and data collector, a computer data processor; and the main steps are: 1) a liquid article to be detected being placed onto a rotary platform which is rotatable; 2) the ray emitted from the radiation source passing through the liquid article, and being received and formed into projection data by the detector and data collector; and 3) the projection data being transmitted to the computer data processor, which processes it to obtain the liquid density of the detected article, compares the result with the densities of dangerous articles in a current database, and then visually displays the detected information of the detected liquid article. Comparing to the prior art, the invention has a small volume, a strong anti-interference, a high accuracy of detection, an easy shielding, and a high use safety and reliability.