PURPOSE: To control a pile jacking input of a pile jacking mechanism so that it may not exceed a specified resistant value in case when pile jacking input is added over a reaction force and prevent a pile jacking and pulling out machine from being inclined and jack in the pile more easily.

CONSTITUTION: Reaction force is detected with reaction force detection devices 12 and 16 mounted to a pile jacking and pulling out machine. This detected value is input into an arithmetic operation device 13 where the detected value is compared with a setting reaction value. In case when the detected value exceeds the setting reaction value, the pile jacking input of pile jacking mechanisms 7, 10 and 11 is controlled so that it may be kept below the setting reaction value, thereby securing the specified reaction force. This construction makes it possible to prevent the pile jacking and pulling out machine from being inclined and jack in the pile accurately, and what is more, smoothly.