Abstract: Alloying technique and manufacturing process are optimized basing on technical characteristics of perforating guns uesd in deep and extra-deep wells,and so the BG155P extra-high strength high toughness tube for perforating gun is developed.Mechanical properties of this type of tube are tested,and perforating tests are conducted.Microanalysis methods such as optical microscope(OM)and electron backscatter diffraction(EBSD)etc.are adopted to analyze the microstructure of the BG155P tube.The test results shows that the BG155P extra-high strength high toughness tube for perforating gun can meet the requirements of a perforating gun using in the environment of 200℃ and 200 MPa.The tube has a grain size above level 10,and an average effective grain size of 2.6 μm;and this type of fine grain is the main reason for its excellent strength and toughness.