Abstract: In order to solve problems caused by difficult re-entry of branched boreholes in CBM multi-lateral horizontal wells, such as the inability to RIH screen and the impossibility to realize the screen completion, a re-entry guide tool for screen completion with hollow structure was developed, the completion technology for multi-lateral borehole in CBM multi-lateral horizontal wells was optimized, and the steps of re-entry screen completion for multi-lateral borehole were proposed, thereby forming the re-entry screen completion technology for multi-lateral CBM horizontal wells. The technology was tested in Well Qinshi 12-1; and the test results showed that by comparing the re-entry guide tool with the borehole trajectory data measured by MWD, and it could be judged whether the re-entry was successful, and the screen could be RIH to the branched wellbore to achieve the screen completion. The results also showed that the re-entry screen completion technology for multi-lateral CBM horizontal wells solved the problems of difficult re-entry and the screen completion.