The active fault-tolerant control for vehicle platoons with actuator fault under prescribed tracking performance is investigated. Considering the actuator partial loss of effectiveness and bias faults, a Luenberger observer and adaptive residual threshold are proposed for fault detection. Based on this, to guarantee the transient and steady state performance of vehicle platoons with actuator fault, a backstepping based fault-tolerant control algorithm under the prescribed tracking performance framework is developed, which is proved to be capable of achieving the bounded tracking errors with prescribed performance, meanwhile the safety, compactness inter-vehicle distance constraints are not violated. The effectiveness of the proposed active fault-tolerant control algorithm is demonstrated via simulation results.