The invention provides an automatic inserting and pulling out device which comprises a fixing base used for fixing a movable inserting piece. The fixing base is connected to a push rod of a push rod driving mechanism in a floated mode. The fixing base is further provided with a guide structure used for guiding and aligning when the movable inserting piece gets close to a fixed inserting piece and carries out insertion. When the automatic inserting and pulling out device is used, the push rod of the push rod driving mechanism stretches out, drives the fixing base to move towards the fixed inserting piece, when the fixing base gets close to the fixed inserting piece, the guide structure on the fixing base performs a guiding and aligning function, floated connection between the fixing base and the push rod guarantees floated alignment of the movable inserting piece and the fixed inserting piece when tiny errors exist during inserting connection between the movable inserting piece and the fixed inserting piece, and the inserting connection precision is further improved.