The invention discloses a treatment method for sinking a steel casing to encounter a boulder, a steel casing structure and a drilled pile, and relates to the technical field of steel casing construction. The treatment method includes the following steps that S1, a first steel casing is inserted at a designed pile location until the bottom of the first steel casing encounters the boulder, and the diameter of the first steel casing is larger than that of a designed pile hole; S2, sweep hole operation is carried out along the inner wall of the first steel casing, the boulder at the hole wall is broken and the pile hole is excavated until the bottom of the pile hole reaches the elevation of a bottom port of the steel casing required by design; S3, a bottom port of a second steel casing is lowered to the elevation of a bottom port of the steel casing, and the diameter of the second steel casing is larger than the diameter of the designed pile hole; and S4, a gap in the first steel casing and the second steel casing is filled with concrete. According to the treatment method for sinking the steel casing to encounter the boulder, the steel casing can be lowered into the designed elevationin the pile hole, and the problem of rolled edge or stuck at the bottom port of the steel casing under the condition of steel casing sinking to encounter the boulder is solved.