In this paper, we propose a designing scheme of ultrahighspeed IEEE 802.11ac WLAN prototype, which implemented on NIPXI platform using LabVIEW graphic language. The system consists of different modules on 802.11ac physical layer, namely, encoder, stream parser, modulator, FFT and their inverses, synchronization, channel estimation as well as equalization. The system can also achieve automatic gain control(AGC) by correcting the antenna magnification with the estimated energy of the received signal, in this way, adaptive modulation is realized. The whole system transmits realtime video data combining with upper computers. Testing result shows that the prototype has good feasibility and applicability, which can achieve low frameerrorrate and high transmission rate, as well as supporting the high rate and high quality video transmission.