The utility model relates to a transfer case of a crawler tractor, in particular to a hydraulic steering transfer case assembly, which mainly solves the technical problems of complicated installation and dismounting, low production efficiency and the like because in the transfer case assembly of the tractor in the prior art, a belt wheel is arranged between a front cover plate and the transfer case, and the belt can be taken out only through firstly dismounting the front cover plate or the transfer case when the maintenance or the replacement is needed. The hydraulic steering transfer case assembly comprises an engine front shaft, a positioning shaft, an engine front cover plate and a front support frame, wherein the positioning shaft and the engine front shaft are connected, the positioning shaft is connected with a third gear, the third gear is engaged with a second gear, the gear transfers the engine torque to a second shaft, the second gear transfers the engine torque to a first shaft through the first gear, the first shaft and the second shaft respectively transfer the engine torque to two gear pumps, the front end part of the positioning shaft is fixed with the belt wheel, a transmission wheel is arranged above the belt wheel, and a belt is arranged between the belt wheel and the transmission wheel.