It is difficult to demolish the water stop wall at the butt end of immersed tube by machinery,and it is more economical and efficient to demolish it by blasting.However,it is still difficult to demolish it by blasting when it is close to the important structure and requires high construction technology.Combined with the example of blasting demolition of water stop wall at the butt end of immersed tube tunnel on Yuliangzhou east line in Xiangyang,the paper introduces the blasting demolition construction technology of water stop wall under the complex conditions of large water depth,thin wall, narrow construction working face,close to the protected buildings and the existence of first-class soil and water conservation organisms.Before the blasting demolition of the two water stop walls,the geological drill is used to arrange the blast holes on the top of the water stop wall with the a width of 1.2 m and the maximum underwater depth of more than 18 m.According to the design explosive consumption of 1.28 kg/m3,the East branch water stop wall was demolished,and the expected demolition effect was achieved.The maximum peak vibration velocity of the permanent support of diaphragm wall adjacent to the explosion source was 8.16 cm/s,the maximum peak vibration velocity of the first section of immersed tube to be floated near the explosion source was 3.7 cm/s,and the maximum overpressure peak of water hammer wave was 0.786 MPa.Based on the summary of Dongcha blasting and considering the actual situation of Dongjin water stop wall,the blasting scheme of Dongjin is optimized.The designed explosive consumption is adjusted from 1.33 kg/m3 to 1.02~1.33 g/m3,which not only the expected demolition effect is achieved,but also the blasting vibration and water shock wave are further weakened.The maximum peak vibration velocity of the permanent support of the diaphragm wall is 7.49 cm/s,The maximum peak velocity of the buried section closest to the explosion source is 5.03 cm/s,and the maximum overpressure peak value of water hammer wave is 0.592 MPa,all of which have no influence.