A method for the determination of the content of each component in the binary surfactant system of octylphenol polyoxyethylene ether (OP-20) and sodium dodecyl sulfate (SDS) was studied and established. The content of OP-20 in OP-20/SDS binary complex system was detected by ultraviolet spectroscopy. SDS had a significant effect on the absorbance and critical micelle concentration (ccmc) of OP-20. After adding 0.3 mmol/L SDS, the absorbance of OP-20 at the maximum absorption wavelength of 224 nm increased from 1.727 to 1.751, and the ccmc decreased from 0.223 mmol/L to 0.198 mmol/L. HP-β-cyclodextrin (HP-β-CD) has a significant masking effect on the detection of OP-20 in the OP-20/SDS binary complex system by ultraviolet spectroscopy. Job's experiments showed that HP-β-CD and OP-20 were included in a molar ratio of 1:1. After adding HP-β-CD, the content of OP-20 in the complex system can be accurately detected by ultraviolet spectroscopy. The recovery rate changed from 96.42% ~ 106.92% to 99.28% ~ 101.38%, the interference of SDS on OP-20 was significantly reduced. The experimental results of FT-IR and 1H-NMR showed that the reason for eliminating the mutual interference between SDS and OP-20 was that the OP-20 molecule entered the HP-β-CD molecular cavity and formed an inclusion complex. The content of SDS in OP-20/SDS binary complex system can be accurately detected by conductivity method， and OP-20 will not significantly interfere with the detection of SDS by conductivity method. When the concentration of OP-20 in the solution is 0.1 ~ 0.3 mmol/L, the recovery rate of SDS in OP-20/SDS complex system is 100.83 % ~ 101.92 %. This method can effectively detect the content of each component in the OP-20/SDS binary surfactant system.