In this paper, a portable and cost-effective 16-channel EEG acquisition system with multiple analog front ends cascaded was designed. Channels required were selected according to chip selecting signal to configure each in a dynamic and personalized manner. In order to test system performance, EEG signals of five subjects from spontaneous state were sent to the host computer through the high-speed wireless module. Related steady-state visual evoked experiment was collected and analyzed. It was observed that obvious alpha rhythm appears during eyes-closed in spontaneous EEG signals; and peak values appears at the corresponding stimulating frequency and harmonics in steady-state visual evoked experiment. The results show that the acquisition system can accurately collect spontaneous EEG signals and evoked EEG signals. Therefore, it is suggested this system can be used in applications of brain computer interface and have certain theoretical and practical values.