Automatic bolt tightening system and bolt tightening control method

The invention discloses an automatic bolt tightening system and a bolt tightening control method.The automatic bolt tightening system comprises a tool mechanism, a variable-pitch driving device and an electric torque wrench, the tool mechanism comprises a base, a floating seat and a telescopic driving device, the base is arranged on one of a bearing inner ring and a bearing outer ring of a variable-pitch bearing, and the floating seat is arranged on one of the bearing inner ring and the bearing outer ring of the variable-pitch bearing; the electric torque wrench comprises a bolt sleeve and a sleeve driving device, and the bolt tightening control method comprises the steps that after the bolt sleeve is aligned to a target to-be-tightened bolt, a telescopic driving device and the sleeve driving device are controlled to act so as to tighten the target to-be-tightened bolt; controlling the telescopic driving device to act to drive the floating seat to move away from the bolt so as to drive the bolt sleeve to sepa