The present disclosure relates to a leveling control method, device and system, a motor grader. The leveling control method includes: acquiring elevations of a current position of a blade of a motor grader and a target position, and a movement speed of the motor grader, wherein the target position is on the ground with a certain horizontal distance from the current position along a movement direction of the motor grader; determining a movement time of the blade from the current position to the target position from the horizontal distance and the movement speed; determining a lifting speed of a lifting cylinder from an elevation difference between the elevation of the target position and the elevation of the current position and the movement time; and controlling the lifting cylinder to adjust the blade to move from the current position to the target position according to the lifting speed.