A super-long thermal insulation steel jacket pipe, comprising a working steel pipe 1 and an outer steel pipe 2, wherein the outer steel pipe is sleeved outside the working steel pipe, an annular cavity 3 formed by a gap is reserved between the working steel pipe and the outer steel pipe; a support frame is disposed between the working steel pipe and the outer steel pipe; the annular cavity is a vacuum cavity, two ends of the outer steel pipe are tightened, a tightened part of the outer steel pipe is sealed with an outer wall of the working steel pipe through several seal rings 4, and the annular cavity is further filled with a phase-change material; the support frame is a spiral annular support frame 5 or a C-shaped support frame (6 Fig 2); when the support frame is the spiral annular support frame, the spiral annular support frame is sleeved on an outer peripheral side of the working steel pipe, and is not in contact with the working steel pipe, and when the support frame is the C-shaped support frame, several C-shaped support frames wind the outer peripheral side of the working steel pipe at intervals.
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