The invention discloses a detergent bottle, a detergent dropping device used for washing machine and a washing machine. The detergent dropping device comprises a bottle body and a one-way valve. A detergent accommodation space are divided in the bottle body, breathable holes communicated with the detergent accommodation space is arranged on the bottle body, and the breathable holes are communicated with a one-way air inlet structure; the one-way valve is connected to the bottle body, the one-way valve comprises a valve body, a valve core and a restoration part, one end of the valve body is communicated with the detergent accommodation space, and the other end of the valve body is provided with a liquid outlet; the valve core is movably arranged in the valve body at the position where the liquid outlet is opened and closed; the restoration part is connected to the valve body and the valve core respectively and drives the valve core to close the liquid outlet. According to the detergent bottle, the detergent bottle can be put in the detergent dropping device directly for use, so as to achieve automatic dropping of a detergent, the operation is simple and convenient, the capacity of the detergent bottle is big, the service time is long, the one-way valve can seal the bottle body after pouring is completed, and the detergent is not prone to deterioration.