Abstract: Combination of one phase of excavation project in Beijing.the Technical problems of bolt supporting structure in deep foundation pit engineering are studied and applied,and the stress of the anchorage cable is monitored at the site.On this basis,by collecting and analyzing a large number of engineering technical data and summarizing the practical experience of Engineering,the change of corresponding force is discussed,and the various factors that cause the stress change are analyzed,the theoretical basis is provided for the stress change of the anchorage cable during the whole foundation pit supporting process.