The wear of cutting tools of EPB shield boring in sandy cobble stratum in Lanzhou is studied, so as to reduce wear of cutting tools and increase the service life of cutting tools.The wear rules of cutting tools are obtained by making comparison between theoretical calculation results and actual practice. Study is made on technologies, i.e. ground conditioning, boring parameter optimization, shield altitude control and shield boring under inadequate soil stress, on basis of study results of cutterhead design and cutting tool arrangement. The service life of cutting tool has been increased; the cutting tool replacing times have been reduced; the construction schedule has been shortened; and the construction cost has been reduced.