The invention relates to a rock sample axial compression device, in particular to a rock sample axial constant acceleration loading test device, which solves the problems that a single-axis compression instrument used in a conversional laboratory only provides constant-speed loading and cannot effectively simulate the periodic pressure of a deep rock stratum. The rock sample axial constant acceleration loading test device comprises a driving system, a loading system, a detection system and a computer data collection system, wherein the driving system, the detection system and the loading system are respectively arranged on a machine frame; the driving system drives the loading system for providing pressure for a test piece; an acceleration sensor is fixed on a plunger rod of a doubles-action plunger type hydraulic cylinder and is connected with the computer data collection system; the plunger rod of the hydraulic cylinder is connected with an upper pressure bearing cushion block. The rock sample axial constant acceleration loading test device has the advantages that the structure is novel; the operation is convenient; through the arrangement of the acceleration sensor arranged on the plunger rod of the doubles-action plunger type hydraulic cylinder, the constant-speed loading of the test device can be ensured; the rock stress state and the change rule under the initial stratumcondition can be simulated in a way much similar to the real condition; wide usability is realized.