The invention discloses a power transmission system for an agricultural electric railway vehicle. The power transmission system comprises a rack, the railway vehicle, a main operation table, a first insulation support, a telegraph pole, a triangular frame, first sliding wheels, input copper lines, output copper lines, a second insulation support, a third insulation support, second sliding wheels, third sliding wheels, first insulation rubber strips, second insulation rubber strips and electric railway wheels. The two first sliding wheels are in rolling connection with a firing line and a null line on the telegraph pole, the input copper lines are embedded in the first insulation rubber strips, the output copper lines are embedded in the second insulation rubber strips, the two second sliding wheels are in rolling connection with the input copper lines, the two third sliding wheels are in rolling connection with the output copper lines, the first sliding wheels and the input copper lines are connected through a wire set, the second sliding wheels and a main switch are connected through a wire set, the main switch and a two-way frequency conversion stroke device are connected through a wire set, the two-way frequency conversion stroke device and the third sliding wheels are connected through a wire set, and the output copper lines and the electric railway wheels are connected through a wire set. The power transmission system has the beneficial effects of being free of pollution, safe and environment-friendly.