Abstract: On the upper part of foundation in the ancient city,there is a large number of miscellaneous fill which is mainly composed of stove ashes and is variable in thickness.With the rapid development of urbanization,to utilize underground space of high buildings is becoming more and more necessary in renovating of the ancient town.Especially,it is serious and crucial to choose a reasonable and economical supporting procedure in excavating deep pit under vulnerable environmental condition such as this miscellaneous foundation.Since any supporting procedure has its limitation,geotechnical engineers should take site engineering geological conditions and feature of foundation pit into account,and choose composite supporting procedures to get better retaining effect.Taking one deep foundation pit of miscellaneous fill for instance,this paper describes its engineering geologic properties,and parameter,design calculation for the anchor rod sheet piling wall and soil nailing wall.This work can provide reference and guideline for the similar engineering to determine its retaining procedure and design of deep foundation pit.