Liquid-crystal　lenses　are　new　devices　for　free　3D　display,　its　photoelectric　properties　are　controlled　by　electric　field.　The　accurate　design　and　optimization　method　of　lens　parameters　were　presented　in　this　paper.　Based　on　the　optical　software　ZEMAX　and　the　focal　length　zoom　method,　the　parameters　of　LCDs　were　designed　and　optimized.　Then,　the　aberration　of　liquid　crystal　lens　and　image　quality　were　evaluated.　it　is　proved　that　the　optimized　liquid　crystal　lens　aberration　decreases　evidently.　The　dispersion　spot　root　mean　square　radius　(RMS)　value　decreases　from　248.118　μm　to　62.192　μm　with　3.5°　view　and　the　optical　modulation　transfer　function　MTF　is　improved.　The　experimental　results　show　that　the　brightness　and　clarity　of　the　diffractive　lens　array　are　significantly　improved.　©　2017,　Science　Press.　All　right　reserved.