The invention relates to a small caterpillar tractor transmission case. The small caterpillar tractor transmission case is characterized in that the transmission case further comprises a remote controller, a receiver, an electromagnetic valve and two small one-way oil cylinders, and two one-way valves of the electromagnetic valve are connected with the two small one-way oil cylinders responsible for left steering and right steering through hydraulic oil pipes respectively; and the receiver is connected with the two one-way valves of the electromagnetic valve and a main valve through wires, power of the receiver is supplied by a tractor power supply, and the receiver is used for receiving various instructions sent by the remote controller and enabling the two one-way valves of the electromagnetic valve and the two small one-way oil cylinders responsible for left steering and right steering to work. The transmission case can achieve manual operation and remote-control operation, remote-control operation and manual operation are easy and do not intervene each other, use is convenient and reliable, power output can achieve positive and negative rotation, various operation requirementscan be met, and the transmission case is suitable for various small caterpillar tractors.