Industrial Ethernet fieldbus EtherCAT is widely used in the field of motion control due to its high speed, high efficiency and good synchronization.Based on X86 platform, a design scheme, design flow and implementation flow of EtherCAT master were proposed. The control network was composed of EtherCAT master, servo controller and servo motor. It was discussed in detail the master kernel transformation, the master process of parsing XML files from the slave station and the clock distribution mechanism for master/slave precise realtime synchronization of EtherCAT.The experimental results show that the developed master is stable and reliable in real time and the error of multiaxis synchronization is on the nanosecond level, which meets the performance requirements to the EtherCAT master in industrial applications.