Shield direct pile cutting construction method

The invention discloses a shield direct pile cutting construction method. The method comprises the steps that before a shield enters a site, a shield tunneling machine is upgraded and transformed, and targeted type selection is conducted, so that the transformed shield tunneling machine has the direct pile cutting capacity; in the advancing process of the modified shield tunneling machine, when a pile foundation needing to be cut off is encountered, the modified shield tunneling machine is used for directly cutting the pile, and in the pile cutting process, construction parameters of the shield tunneling machine are optimized according to different distances from a cutter head of the shield tunneling machine to the pile foundation so as to reduce abrasion of the cutter head of the shield tunneling machine; according to the method, the pile foundation structure is continuously tracked and monitored after pile cutting, secondary grouting reinforcement is carried out through a grouting hole reserved in a pipe pi