This article investigates the problem of fault-tolerant control for stochastic high-order fully actuated systems (FASs) with actuator faults. Different from the majority of existing studies focusing on deterministic high-order FASs, this work introduces stochastic disturbances into the systems. Employing the generalized martingale technique, a novel fault-tolerant equivalent controller is formulated. Additionally, an adaptive compensation law is constructed to address time-varying faults promptly. The designed preclosed-loop strategy advocates the advantage of the FAS methodology and guarantees performance by ensuring that the tracking error complies with the user-defined probabilistic ultimate bound. Finally, a numerical case and a practical example of a rotary steerable drilling platform are exploited to demonstrate the effectiveness of the proposed method.