In the radar systems, such as frequency source, power amplifier, mixer, filter and A/D converter, ageing devices, temperature and environmental changes etc., it is inevitable to introduce wideband amplitude/phase error. These can cause seriously channel mismatch that will affect the performance of digital beam-forming, synthetic aperture radar image, space time adaptive processing (STAP), automatic target recognition (ATR), target detection, clutter/interference suppression, pulse compression results and cancellation ratio etc. So this study mainly discusses that the channel amplitude/phase inconsistency of wideband digital array radar affects the pulse compression, beam forming and so forth. It also researches and analyses channel equalisation method, and the simulation and experimental results based on the experimental data show that the method based on Fourier transform is effectively and convenient. The Fourier transform method is easier for hardware implementation that can be applied to practical engineering.