Concrete filled steel tubular( CFST) truss girder is a new composite structure,for which the concrete strain status is defined as a key index of structural behavior.However,the member slenderness and the tube diameter of chord are so small that it is rather difficult to measure concrete strain.Based on experimental study on structural behavior of CFST truss girder,a kind of embedded concrete strain gauge with accessory location adjustment configuration are developed,and the special mix method for self-compacting concrete with normal strength grade and concrete pouring technique are also designed.It is verified by the experimental test that,the concrete strain measuring technology developed for infilled concrete of small-diameter but slender CFST members can help to minimize structural injure,cut cost and is convenient for engineering design and construction.The technology can be further applied for experiment of laboratory small scale model and in-situ construction of new composite structures like CFST truss girders.