Engineering machine and its main arm, and method for detecting and correcting side bend of the main arm

The present invention discloses a method and a construction machine main arm, and the detection side of the main arm of construction machinery correct camber, arm construction machine comprising a main body (10), wherein the construction machine further comprises a main arm body disposed mounting portion (21) and the support portion scalable, one end of the support portion of the support means (20) (10) on both sides of the support means (20) includes a connection to the body (10) is connected to the said body (10) of the head, the other end connected to the mounting portion (21). The present invention may be supported by the support body portion scalable, and can be detected next camber correction and lateral bending provided.