The　anchored　bracing　pile　is　more　widely　and　more　applied　beyond　its　theory.　Dynamic　data　of　steel　bar　stress　and　horizontal　displacement　along　piles　are　analyzed,　and　the　distribution　rules　of　internal　force　and　deformation　are　gained.　Based　on　steel　bar　force　and　section　curvature,　two　methods　to　calculate　bending　moment　along　pile　are　deduced.　Comparison　between　the　m　method　and　the　equivalent　beam　method　indicates　that　moment　distribution　is　similar,　but　its　numerical　value　is　very　discrepant.　The　m-method　has　the　largest　bending　moment,　and　the　in-situ　measurement　has　the　smallest　bending　moment.　So　the　traditional　design　methods　have　large　optimization　space.　Theoretically　it　can　save　half　quantities　of　steel　bars,　which　are　less　collocated　near　the　central　axis.