Abstract: Prestressed anchoring technology is widely used in coal mine roadway roof support, but at present, the disassembly of mine anchors is still carried out manually. In the process of disassembly, the disassembly load is high, and the remaining load of anchor cable after disassembly is not zero, so the safety of the disassembly process is poor, and the subsequent operation has security risks. This paper takes B-type mine anchorage as the research object, establishes the sub-field model during its disassembly, analyzes and determines its key problems, and carries out the structural improvement design of mine anchorage based on the sub-field model transformation method, and carries out the structural optimization with the assistance of the unloading experiment. Finally, an improved detachable mine anchor is proposed and tested in underground. The test results show that, compared with the commonly used mine anchors, the proposed demountable mine anchors after structural optimization can achieve rapid and efficient removal, and at the same time, the removal force of the anchors is small, the residual stress of the anchor cable is zero, and the unloading process is safe and reliable.