Ground blasting vibration control is one of the key contents in the blasting construction of subway tunnels in complex urban environment,and cut blasting is the key to determine the blasting vibration intensity.Combined with the actual project of the north extension line of WuHan Metro Line 7(Qianchuan Line),an optimization design was carried out on the basis of the original blasting cut method.The numerical simulation and field vibration test verification methods were used to calculate and compare the blasting vibration effects of single wedge cutting,burn cut with four holes and double wedge cutting.Then,the optimization method of cut blasting was proposed.The results show that single wedge cutting,burn cut and double wedge cutting have similar propagation rules of blast vibrations along the axis of tunnel excavation.The peak vibration velocity along the x direction(horizontal radial) decreases with the increase of the distance from the working face in the range of 0~-5 m.When distance exceeds 5 m,the peak vibration velocity increases first and then decreases.The excavated area of the upper bench of the left pilot tunnel has an amplification effect on the surface vibration velocity,which is referred as a “cavity effect”.The distribution of the x-direction(horizontal radial) peak vibration velocity on the left and right sides of the tunnel is roughly similar,and gradually decreases with the increase of the horizontal absolute distance from the origin along the direction perpendicular to the axis of tunnel excavation.The upper bench of the left pilot tunnel has a free face,which makes the peak vibration velocity along the x direction(horizontal radial) on the left side of the tunnel bigger than that on the right side.Due to the delayed initiation,the peak vibration velocity along the x direction(horizontal radial) by double wedge cut blasting is the minimum.The surface vibration velocity of the excavated area is 1.35~2.02 times than that of the unexcavated area ahead during the tunnel blasting construction,due to the “cavity effect”.Compared with other cutting methods,the “cavity effect” of the double wedge cutting is weaker.The comparative analysis of blasting vibration intensity of the three kinds of cutting modes shows that the order of advantages and disadvantages of the three kinds of cutting modes is: double wedge cutting>single wedge cutting>four straight hole cutting.