Since the traditional redundancy for fault tolerance of a control system is complex in structure and expensive, a novel method for fault tolerance of multiprocessor-structured control system by hardware and software reconfiguration is presented. Based on the fact that the control system is composed of several processors, this method performs fault detection by self-diagnosis implemented in each processor and validation of exchanged information between the processors, tolerates fault by hardware and software reconfiguration carried out by monitoring and configuring device. Security strategy and operation mode were presented. The principle of the monitoring and configuring device was discussed in detail. The method was proved by a control system of dc motor and got a satisfied result.