The invention discloses a hydraulic system of an outdoor performance robot. The hydraulic system comprises a fuel tank, a motor unit composed of at least one main motor, a main pump unit composed of at least one main pump and a main valve unit composed of at least one main valve. The output end of the motor unit is connected with the main pump unit, the output end of the main pump unit is connected with the main valve unit, the output ends of the main valve unit are respectively used for controlling operation of a primary arm cylinder, a secondary arm cylinder, a ternary arm cylinder, a rotary motor and a wing cylinder. The hydraulic system is simple in structure, accurate in control, large in output power, high in power/mass ratio, capable of realizing stepless speed regulation, free of shock and easy for remote drive control.