Abstract：Aiming at the problem of poor blasting effects that exists universally in hard rocks，the middle deep hole blasting tests were done in hard rock tunnels at Shuangyang Mine；and the blasting test results of different kinds of cutting forms have been gotten. Through comparison，the compound barrel cutting is proved to be completely fit for middle deep hole blasting；and the utilization rate is high. At last，some valuable achievements of tunnel blasting are summarized，and the least space between holes that can abstain passive effects of explosives is proposed. The charging length of cutting holes is calculated in terms of theory. According to the construction of Shuangyang Mine，some concrete improving suggestions and technological methods that can raise the blasting effects are presented. By adjusting production organization，not only is the efficiency raised but also the costs are reduced on the basis of former equipment levels producing substantial economical benefit and offering reference to other similar works.
