The invention relates to a radiation therapy device of a multi-alignment body which comprises a shield, and a source body and a final alignment body which are arranged on the shield, wherein a plurality of radioactive sources are loaded in the source body, at least one middle alignment body is arranged between the source body and the final alignment body, the source body, the middle alignment body and the final alignment body are respectively connected with a gear power transmission mechanism, which can independently rotate relative to the same rotary center line, the final alignment body comprises various groups of through holes with different diameters, the middle alignment body comprises at least one group of though hole, at least one group of through hole in high-latitude regions and at least one group of through hole in low-latitude regions. In the process of treatment, the invention can automatically combine radiation beam according to the need of treatment proposal, the dynamic conformity of a dose field is realized, the auxiliary time of the radiation therapy is shortened, and the efficiency of the radiation therapy is improved.