A detection system of blood oxygen saturation was developed. Based on Texas Instruments (TI) AFE4400 chip,the acquisition circuit of blood oxygen simulation was designed,and TivaTM Cortex-M4 was used as the processor and the control core. AFE4400 can simplify the circuit design,reduce the power consumption and decrease the size of the circuit,which lowers the cost,improves portability and improves the consistency of system calibration. TivaTM Cortex-M4 has enough processing abilities and storage space to realize signal processing and data storage. In the process of design,the denoising effects of several filter algorithms based on wavelet were compared,and the system achieved the optimal filter algorithm by making full use of TivaTM Cortex-M4′s processing capacity. After debugging and calibrating the system,the system realizes the function of blood oxygen saturation detection.