The present invention relates to the art of medical imaging devices. The present invention discloses a cross arm of X-ray equipment, comprising a guide provided on the cross arm and a tube provided on the guide, wherein the cross arm further comprises a linkage device, such that the tube can be driven to move along the guide when the cross arm rotates. When the cross arm is rotating, the tube can move with the cross arm, thereby reducing operation steps and improving maneuverability and convenience of equipment. Moreover, adjustment of SID can be completed automatically without being towed by a motor, thereby reducing equipments costs and improving market competitiveness.
