Flexible steering brake device for harvester

The invention belongs to the technical field of harvesters, and provides a flexible steering brake device for a harvester in order to solve the problem that a gearbox bears great impact during steering of the harvester. The device includes a left running caterpillar band, a right running track and a steering brake device body. The steering brake device body includes a valve, a handle, a directionchange valve element and an overflow valve element. A direction change valve chamber and an overflow valve chamber, which extend in the vertical direction and are communicated mutually, are formed inthe valve body, and the intensity of pressure of the overflow valve chamber increases gradually when the overflow valve element moves. By the direction change valve chamber and the overflow valve chamber formed in the valve body of the steering brake device body, the overflow valve element is used for increasing the pressure of the direction change valve chamber, the brake degrees of a left powerdevice and a right power de