The utility model discloses a trolley support suitable for variable cross section tunnel relates to trolley support technical field, including portal main part, telescopic spare is set up on portal main part, and it includes: the outer tube is axially horizontal and is arranged at the top of portal main part, and both ends are connected with outside, the
threaded rod is coaxial and is arranged in the outer tube, and the annular gap is left between the outer wall of
threaded rod and the inner wall of outer tube, the threaded cylinder is nested in the annular gap, and its inner wall is in threaded engagement with
threaded rod. The utility model with the axial movement of threaded cylinder relative to outer tube in telescopic spare, can accurate regulation trolley support node's geometric size. Since the outer tube and threaded cylinder initial state both ends are flush, and the length is same, through rotating knob, can make telescopic output end's length of protruding according to actual demand change, thereby let same trolley support can match different size's tunnel section, need not for each kind of section alone custom-made trolley support, has greatly promoted the versatility of equipment.