A new calculation method has been established in order to obtain the clip rock of small-distance tunnels blasting cumulative damage rule. The new method is applied to predict Dapingshan tunnel clip rock blasting cumulative damage during construction; at the same time a field test validation is carried out. The results show that: the new method can not only reflect the blasting of mechanical action process

and the calculated parameters are also easy to obtain; the prediction and measured average error is about 12%

which can be used to predict rock cumulative damage; Dapingshan tunnel clip rock cumulative damage rule is as follows: after the second blasting

6 test holes velocity average drop rate is 4.3%; the largest test holes cumulated damage in increments is 6.1%. The results provide a basis for further small-distance tunnels clip rock stability studies.