An array micro Faraday cup ion current detector is presented. With its design，a simpler and smaller High-field Asymmetric Waveform Ion Mobility Spectrometry(FAIMS) could be achieved. Compared with other types of detectors, it has advantages in simplicity, stability, low noise, high measuring range, and atmosphere compatibility. The Array Micro Faraday Cup(AMFC) is made up of three parts:grid electrode, sensing array and shielding electrode,in which the sensing array is formed by dozens of 200-micron-diameter silicon cylinders in a staggered arrangement. The structure of the micro Faraday cup can be fabricated in a typical MEMS fabrication process, for it is totally compatible with the planar FAIMS micro chip. Fluent simulation results show that the design could realize a small fluid resistance force, and the flow field of the carrier gas is in favor of a better absorption of the ions. When it is combined with a KEITHLEY 237 electrometer, the noise level of the AMFC is about 0.5 pA, while the output signal of an acetone sample is about 120 pA. Obtained results show that the AMFC satisfies the requirements of FAIMS systems.