Data acquisition card or Daisy chain serial model are widely used in energy monitoring system, but there are still problems to be solved such as the unity of data specification and performance of real time is not high. We proposed that using signal conversion module to unified signal, using serial port servers to achieve standard Modbus RTU protocol to TCP/IP protocol conversion, supplemented by optical fiber transmission to collect data. Thus realizing the unity of data acquisition specifications and improving the data transfer rate and real-time performance, also solving the problems of points dispersion, distance is too long and can not eliminate interference.