The invention discloses a single-double combined boom structure of a crane, which comprises a lower boom section, an upper boom section and a transition joint, the lower boom section is of a double-arm structure, the two sides of the lower boom section are symmetrical, and the upper boom section is of a single-arm structure; the arm support lower section is formed by sequentially connecting a root part, a root part section and a lower section standard section, and the arm support upper section is formed by sequentially connecting an upper section standard section and a head section; the upper arm support section and the lower arm support section are connected through a transition joint. The upper section of the single-double combined
cantilever crane structure is the single arm, the lower section of the single-double combined
cantilever crane structure is the double arms, the transition joint is arranged at the transition position of the single arm and the double arms,
lateral stability is good, and meanwhile arrangement of a connecting beam is avoided. Compared with a single-arm boom, the
lateral stability of the single-arm and double-arm boom structure is better, the
self weight of the single-arm and double-arm boom structure is lighter, and the single-arm and double-arm boom structure has obvious advantages in the aspects of
technical feasibility, safety, economical efficiency and the like; each rod of the transition joint adopts a circular tube section, and the transition joint is symmetrically arranged in structure and is compact in structure and reasonable in force transmission.