The invention relates to a portable electroencephalogram detection system which comprises a background cloud computing server, an intelligent mobile phone terminal and a headband hardware convenient to carry, wherein a headband is composed of a singlechip, an electroencephalogram sampling chip, an electrocardio sampling sensor, a temperature-and-humidity sensor, a wireless data transmission module, a forehead camera, a forehead detection electrode and a power supply system. A power box, a metal electrode, a sensor group, a camera and a main electric box are fixed on the headband, the sensor group is located on the camera, and the power box, the metal electrode, the sensor group, the camera and the main electric box are connected through conductive wires fixed inside the headband. The output end of the metal electrode is connected with the input end of an electroencephalogram signal amplifier, the output end of the electroencephalogram signal amplifier, the output end of a microphone, the output end of the sensor group, and the output end of the camera are connected with the input end of the singlechip, the output end and the input end of the singlechip are connected with the output end and the input end of a wireless communication module in a double-way mode, and the output end and the input end of the wireless communication module are in wireless connection with the output end and the input end of the intelligent mobile phone terminal, and the input end and the output end of the background cloud computing server in a double-way mode.