Bottle and bottle cap device thereof

A bottle cap device, comprising:

• an inner cap having an inner-cap outer ring and an inner-cap inner ring, a joint connected with a bottle neck being defined between the inner-cap outer ring and the inner-cap inner ring;
• an outer cap having an outer-cap outer ring, an outer-cap inner ring and a guide tube, the outer-cap outer ring being threadedly connected with the inner-cap outer ring, the outer-cap inner ring penetrating through the inner-cap inner ring, a lower end of the outer-cap inner ring protruding a distance from a lower end of the inner-cap inner ring, and the guide tube being arranged to extend in the outer-cap inner ring, providing a guide passage of liquid pipe;
• and
• an end cap having an end-cap hole, where the distance is sufficient to allow the end cap to be connected with the lower end of the outer-cap inner ring in a releasably sealing manner, and when the outer-cap outer ring is turned from the inner-cap outer ring toward a loosening direction, the distance is sufficiently shortened to allow the end cap abutting with the lower end of the inner-cap inner ring, and by means of the thrust formed by the abutting, the end cap is made to release from the lower end of the outer-cap inner ring, while the end cap is connected with the lower end of the inner-cap inner ring in a releasably sealing manner, the guide tube is connected with the end-cap hole in a sealing manner, such that a stockage space encircling the guide tube is formed inside the outer-cap inner ring.