A kind of cold rolled aviation tube of TA18 type that has been subjected to recrystallization annealing treatment to produce an uniform initial texture. Subsequently, these tubes were subjected to a second round cold rolling again by the same deformation amount (60%) but different Q ratios (1.1-2.0). On this basis, the influence of cold rolling Q ratio on the plastic deformation texture evolution of TA18 aviation tube was studied by using the electron backscatter diffraction (EBSD) technique, in terms of the In-Grain Misorientation Axes (IGMA) and microstructures of cold rolled tubes with different Q ratios. The results show that the cold rolled tubes with different Q ratio present a "river like" fiber structure along the axial (RD) direction, showing the typical characteristics of large plastic deformation. With the increase of Q ratio, the grain orientation changes from the tangential direction (TD) to the one close to the normal direction (ND). The cold rolling Q ratio has a synergistic effect on the plastic deformation behavior and texture evolution of TA18 tube: with the increase of Q ratio, the Taylor axes distribution changes from <0001> to <10\overline{\mathrm{1}}0>, and the plastic deformation mechanism of cold rolled tubes changes from prismatic slip to pyramidal slip. The reason may be that when the Q ratio increases, the c axis of grains continuously shifts from TD direction to ND direction, and the Schmid factor of conical slip systems increases, which leads to the easy start of conical slip systems; At the same time, the <0001>//ND texture gradually replaced the <0001>//TD texture as the main texture type, and the radial texture factor at the base of the tube was continuously enhanced. In accordance with the AMS standard, when the cold rolling Q ratio is ≥ 1.49, the contraction strain ratio (CSR) of TA18 tubes meets the requirements.