The invention discloses a steel tube arch main arch splicing and supporting system and belongs to the technical field of bridge construction. The steel tube arch main arch splicing and supporting system comprises a support frame (7) and a plurality of herringbone supports (2), wherein the support frame (7) corresponds to the top of a steel tube arch main arch and is arranged below the steel tube arch main arch; the herringbone supports (2) correspond to steel tube arch main arch splicing interfaces at two sides of the support frame (7) and are arranged below the steel tube arch main arch splicing interfaces; the support frame (7) is of a parallel chord type trusswork; the lower part of the support frame (7) is fixedly connected with a foundation; each herringbone support (2) comprises two steel tube upright posts which are arranged in a herringbone shape; the top ends of each pair of steel tube upright posts are fixedly connected together; a supporting platform (5) is arranged on the upper parts of each pair of steel tube upright posts; the lower parts of the herringbone supports (2) are fixedly arranged on a support foundation (1); longitudinal bridge direction connecting supports (3) are fixedly connected between each pair of steel tube upright posts of the herringbone supports (2); a bridge direction connecting support (4) is fixedly connected between two adjacent herringbone supports (2). The steel tube arch main arch splicing and supporting system is simple in structure, convenient and rapid to construct, safe in construction and low in construction cost.