The invention discloses a rock sample fixing device in a three-jaw chuck limiting pull-pressure cyclic test. The fixing device is composed of a lower clamp and an upper clamp; the lower clamp comprises a lower joint connected with a loading seat at the bottom of a test machine, a lower end cap for fixing a sample, a lower chain for connecting the lower joint and the lower end cap, a first center limiting mechanism, a second center limiting mechanism and a first hydraulic mechanism; the upper clamp comprises an upper joint connected with a loading base at the top of the test machine, an upper end cap for fixing the sample, an upper chain for connecting the upper joint and the upper end cap, a third center limiting mechanism, a fourth center limiting mechanism and a second hydraulic mechanism; each center limiting mechanism is composed of a three-jaw chuck, a support component and an adapter plate; one end of each support component is connected with the corresponding adapter plate, and the other end of each support component is connected with the corresponding three-jaw chuck; each of the first hydraulic mechanism and the second hydraulic mechanism comprises a circular annular piston and a circular annular cylinder combined with the circular annular piston.