Deep-excavated　foundation　engineering　is　common　in　Beijing　area,　while　the　related　monitoring　and　theoretical　researches　are　not　quite　sound.　Through　the　monitoring　and　researches　on　pulling　force　of　bolts　in　the　supporting　project　of　foundation　pit　at　Land　No.　4　Group　C,　Wangjing　A1　District,　it　is　deducible　that　the　project　is　quite　distinctive　as　the　change　tendency　of　pulling　force　of　the　two　lines　of　bolts　are　opposite.　It　is　reflected　by　the　incompleteness　of　the　current　regulations　and　the　strong　geographical　characteristics　of　excavation　projects.　The　displacement　monitoring　of　piles　should　be　introduced　into　the　project　so　to　ensure　its　safety　and　to　provide　detailed　data　for　its　design　optimization　and　cost　reduction.　It＇s　recommended　that　when　the　pulling　machines　in　construction　are　available,　axial　force　meters　of　bolts　should　be　used　firstly　to　quantify　the　pre-stressing　loss　locked　so　as　to　optimize　the　construction　parameters　properly　in　accordance.　Therefore,　it　follows　that　there　exists　vast　room　for　the　optimization　for　the　current　excavated　foundation　engineering.　The　research　results　may　provide　reference　and　foundation　for　similar　engineering　design.