The invention relates to a control method of a large engineering manipulator. Each section of arm support of the manipulator is provided with a drive mechanism which can drive the arm support to rotate within a set angle range. The control method comprises the following steps: acquiring the current offset of the drive mechanism and obtaining a control instruction, calculating the offset needed bythe drive mechanism according to the current offset and the control instruction, controlling the drive mechanism according to the needed offset, and driving the manipulator to act. The invention alsoprovides a control system of a large engineering manipulator. The invention realizes precise control of the manipulator through acquiring the current offset of the drive mechanism and according to the current offset, the structural characteristic of the manipulator and the control instruction.