Flat-pushing control method and device of excavator and excavator

The invention provides a flat-pushing control method and device of an excavator and the excavator. The flat-pushing control method of the excavator comprises: controlling a bucket rod cylinder to push a bucket to operate according to control instructions of operators; acquiring gesture changing of a bucket rod in real time; and performing feedback control on oil-inlet amount of a movable arm cylinder according to the gesture changing of the bucket rod so as to enable a bucket to be at the preset height. In flat-pushing operation, the operators of the excavator give out cylinder extending orders to the bucket rod cylinder by controlling an operation device of the bucket rod and perform feedback control on the movable arm cylinder according to the bucket rod gesture measured in real time, so that the inclined angle formed by a movable arm and the horizontal plane and the inclined angle formed by the movable arm and the bucket rod change in matching mode, changing of the movable arm is used for coordinating chan