The invention discloses a high-altitude tree branch saw-cutting device. The device comprises a shell, a guide plate vertically stretching out is arranged on the shell, a saw chain is arranged on the guide plate, a pin shaft is arranged on one side of the shell through vertical connection, and an outer sleeve is arranged on the pin shaft through rotating connection, a spring clamp is arranged between the outer sleeve and the pin shaft through elastic connection, an inner sleeve rod is arranged on the outer sleeve through telescopic sleeve connection, a tension spring connected with the inner sleeve rod is arranged in the outer sleeve, and an arc-shaped tow hook hanging branches is arranged on the inner sleeve rod;, the tail end of the arc-shaped tow hook is the free end, and the free end and a stop pin limiting the outer sleeve are located on the same side relative to the guide plate. Accordingly, the structure is reasonable, by means of the arc-shaped tow hook and the guide plate provided with the saw chain, the branches are crosswise fixed and saw-cut, the whole device is connected with the branches into a whole, the phenomenon that the branches shake, and influences are generatedis avoided, and the technical problem that in the prior art, a tree branch saw-cutting device is inconvenient to use is effectively solved.