The embodiment of the invention provides an M-stage support anchor pipe, and relates to the technical field of tunnel engineering equipment. The M-stage support anchor pipe comprises a flower steel pipe, M stages of support unfolding wall sets and an unfolding wall opening rod; the M stages of support unfolding wall sets are sequentially arranged on the flower steel pipe at intervals, at least twosupport unfolding walls in any stage of support unfolding wall sets are rotatably connected with the flower steel pipe, and M is an integer greater than or equal to 2. The unfolding wall opening rodis used for pushing at least two support unfolding walls to rotate relative to the flower steel pipe from a state of being embedded in the flower steel pipe to a state of being unfolded outside the flower steel pipe when rotating in the flower steel pipe, wherein N stages of support folding wall sets are in the unfolded state, and N is a positive integer smaller than or equal to M. According to the actual properties of weak surrounding rock, the N stages of support folding wall sets matched with the actual properties can be pushed by the unfolding wall opening rod to be in the unfolded state,so that under the condition that the properties of the weak surrounding rock are different, the M-stage support anchor pipe can also be stably fixed in the weak surrounding rock.