Abstract: In order to obtain comprehensive brain activity information conveniently in real time, this study designs a portable EEG and blood oxygen synchronous acquisition system for real-time monitoring of brain functional activities. The EEG electrodes filter and amplify the detected EEG signals, and send them to the microprocessor via Bluetooth to analyze the EEG data; the photoelectric probe converts the optical signals into electrical signals, which are amplified and separated, filtered, and AD converted, calculates the brain's oxygenation and blood-red protein (ΔHbO₂) and blood-red protein (ΔHb) by amplification of Lambert-Beer law. Finally, experiments with commercial instruments NuAmps and Oximeter show that the system can calculate ΔHbO₂ and ΔHb while collecting EEG signals.