In accordance with the requirements of industrial mechanical vibration field data real-time transmission in the condition of multi-survey-point and mass data acquisition, an Ethernet data transmission method based on Ethernet controller RTL8019AS and TMS320C5402 DSP is presented. Packing data from A/D into UDP and IP package and controlling RTL8019AS through I/O mapped registers, high-speed DSP makes real-time communication high performance. Ethernet frame protocol and TCP/IP protocol are simplified for the specific purpose. And the interface technology between Ethernet controller RTL8019AS and DSP is solved. The system evaluation and debugging are made.