A microcoil-array-based multichannel wireless implantable neural stimulator for power and data transmission is developed. The microcoil array is fabricated using four processing technologies, namely enameled wire, printed circuit board (PC H), flexible printed circuit board (FPC), and 4-layer FPC. The coupling efficiencies of the coils are tested under ideal coupling and with spatial mismatch. The experimental results indicate that the decline of output voltage is less than 15% for all microcoils if the horizontal mismatch is less than 3 mm and the angular mismatch is less than 30°. The results also demonstrate that FPC coils produce a higher output voltage than that produced by PCB coils of equal size. The 4-layer FPC coils produce the highest output voltage for a given coil size. An experimental multichannel transmission device is built with a 2×2 microcoil array. The preliminary results show the feasibility of using a microcoil array to achieve multichannel transcutaneous transmission of neural electrical stimulation.