Where rivercrossing tunnels are built by means of shield machines, the shield machines will conduct boring works underneath the river, which results in great risks for the tunnelling equipment. Furthermore, where the fissure water in the ground is connected with the river water, the difficulty for the boring of the shield machines will be increased, which has fundamental impact on the success/failure of the works. Therefore, adequate measures must be taken to ensure that there will be neither breakthroughs between the tunnel and the river nor breakdown of the equipment. This article makes some comments on the equipment preparations for the boring construction of shield machines crossing underneath rivers, which can provide reference for the sucessful boring construction of shield machines in similar works.