The invention provides a method for changing positions of automatic measuring system prisms in a tunnel construction hole. The method comprises the following steps that an automatic measuring system comprises a necessarily measured prism 3#, an optionally measured prism 1# and an optionally measured prism 2#; the position change of the prism 3# in the automatic measuring system refers to the rightward change on a left turning curve and the leftward change on a right turning curve; before a shield machine reaches a curve section, the preparation work for changing the position of the prism 3#, including the new position selection and the new support frame manufacturing is made; before the machine halt of the shield machine, a machine body of the shield machine during the machine halt is enabled to be in a linear state; a measuring system is used for measuring the posture of the shield machine in three times, and artificial records are made; the prism 3# is moved to a new position, the relative relationship between the prism 3# and the shield machine is calculated again according to the operation mode of the shield machine before the initial starting, and change is carried out; the posture of the shield machine is measured again; when the comparison result with the former record is smaller than 2mm, the completion of the current prism change is confirmed; when the comparison result is greater than 2mm, the initial starting errors in each step are checked, or the prism 3# is recovered to the original position, and the steps are repeated. The problems that the automatic measuring system in the tunnel construction hole requires station change every day, and the work efficiency is low are solved, and the characteristic of high construction efficiency is realized.