The invention discloses a threaded connection structure for a bottle cap and a bottleneck. The threaded connection structure comprises the bottleneck, and an external thread is formed on the outer wall of the bottleneck. An internal thread is formed on the inner wall of the bottle cap, and the bottle cap is assembled on the bottleneck in a threaded manner. One side of the bottle cap vertically extends downwards to form an extending part, and a rotary shaft is perpendicularly and rotationally mounted on the extending part. A shaft end bulb of the rotary shaft is clamped into a spiral groove ofthe external thread of the bottleneck and is in relative sliding fit with the spiral groove. The threaded connection structure has the beneficial effects of being simple in structure and convenient touse, the bottle cap can be completely separated out of the bottleneck, and meanwhile the bottle cap cannot be separated from the bottleneck.