A method and a device for processing signal sampling point data (IQ data), the method includes: transforming time-domain signal sampling point data to be transmitted into frequency-domain signal sampling point data, encoding the frequency-domain signal sampling point data and then sending out. The technical solution uses the frequency-domain characteristics of IQ data in an LTE system, firstly transforms time-domain IQ data into frequency-domain IQ data, removes redundant information, then performs encoding and reduces the number of encoded points at a sending terminal to realize more effective compression of CPRI data in the LTE system, satisfy requirements on transmission bandwidth of current transmission access networks, and can realize quick and controlled high-efficiency compression and decompression functions of CPRI data in an LTE radio base station system.