The utility model discloses a caterpillar crane speed reducer. An input gear shaft (5), a gear shaft (7), a second output shaft (9) and a first output shaft (3) are respectively installed in bearing supports of a box body (1) through bearings arranged at two ends of the input gear shaft, the gear shaft, the second output shaft and the first output shaft, a transmission gear (4) is arranged on the input gear shaft (5), a transition gear (6) is positioned on the gear shaft (7), a second output gear (8) and a gear (10) are installed on the second output shaft (9), a first output gear (2) is installed on the first output shaft (3), the first output gear (2) is meshed with the transmission gear (4), the input gear shaft (5) is meshed with the transition gear (6), the gear shaft (7) is meshed with the second output gear (8), and finally the speed reducer is integrally formed. The caterpillar crane speed reducer has the double functions of lifting heavy articles and driving hydraulic pumps to work and is simple in structure, light in weight, large in bearing capacity and stable and reliable in working.