The A/D devices used in automatic weather stations and the authenticated devices are usually 12 bits or below, because the stability and accuracy of data conversion are determined by the bits of A/D devices, which cannot meet the needs of new meteorological equipment. Using the 24bit serial A/D device, AD7714, produced by Analog Devices Company, is used in the design of the new circuit s for the operational system. The functions and characteristics of AD7714, some of the source codes, and the AD7714based design methods of software and hardware are introduced. Besides, some technical problems encountered in practical application are discussed.