In order to solve the problem of rapid support after mechanized excavation in soft surrounding rock tunnel, three arm rock drilling platform and pneumatic plate hand are used to carry out rapid support to the surrounding rock. The construction principle and process flow of the TB/T 3356 are summed up through the application of the high shell prestressed hollow bolt under the mechanized construction condition of the large section of the weak surrounding rock section of the iron Gaojiaping Tunnel of ZhengzhouWanzhou Highspeed Railway, and the proportion of the grouting for the tunnel bolt is put forward and the axial force of the bolt is combined with the grouting test. Monitoring and displacement monitoring fully verify the advantages of the bolt fast confining the surrounding rock, forming stress arch, reducing the surrounding rock loosening circle and ensuring the stability of the surrounding rock, ensuring the safety of the tunnel mechanization construction, improving the mechanized construction efficiency of the tunnel, and applying the large mechanized section to the weak surrounding rock section of the tunnel. It is of great significance to design and optimize the design of support.