In order to study the bearing capacity of steel micro-tube pile in advanced support in deep foundation pit of earth and rock under different working conditions, the in-row pile of one double-row steel pipe pile was used as the test pile for field test, based on a soil-rock foundation pit project in Qingdao. The strain gauges were symmetrically installed on both sides of the pile surface, and the strain values of the test steel tube pile under different excavation depths and construction conditions were measured. The distribution and variation rules of the bending moment of the steel tube pile were discussed. The test results showed that twenty two strain gauges survived during the test, and the strain gauge installation method was feasible and reliable. With the increase of foundation excavation depth, the pile bending moment showed an increasing trend, and the distribution law along the depth was large up and small down. Anchor cable and anchor cable locking can significantly reduce the pile bending moment. It can be seen that double-row steel micro-tube piles combined with prestressed anchor cable and bolt has a good supporting effect in the foundation pit of earth-rock combined stratum. The test results can provide reference and basis for the design of steel micro-tube pile in earth-rock combined stratum.