The utility model discloses an anchoring mechanical arm used for a soil engineering centrifugal test. The anchoring mechanical arm comprises a support rack, a guide rod adjusting rack, a guide rod, a guide rod fixing rack, a hydraulic cylinder support rack, a press rack hydraulic cylinder, a press rack, an adjusting rod, a press plate and hinge plates, wherein the lower front end of the support rack is fixedly connected with the top end of the hydraulic cylinder support rack; the lower rear end of the support rack is connected with the upper end of the guide rod adjusting rack; the bottom end of the hydraulic cylinder support rack is fixedly connected with the press rack hydraulic cylinder; a piston rod of the press rack hydraulic cylinder is connected with the press rack; the guide rod fixing rack is fixedly connected with the middle section of the hydraulic cylinder support rack; both ends of the guide rod are respectively connected with the guide rod fixing rack and the guide rod adjusting rack by the hinge plates; the top end of the press rack is sleeved on the guide rod; the bottom end of the press rack is connected with the press plate; and the press plate is connected with the press rack by the adjusting rod. According to the anchoring mechanical arm, the guide rod can be adjusted, and an anchor rod can be anchored to a model with different angles. An anchor plate can be firmly grasped below the press plate due to the arrangement of locking hooks so that a centrifugal field adapted by the anchoring mechanical arm reaches up to 150g.