目的 利用氮冷等离子体改性KDP晶体表面，实现高质高效的液膜接触潮解抛光。方法 利用氮冷等离子体实时处理潮解抛光界面，实现微汽雾中的液滴在KDP晶体表面由液滴驻留向液膜接触转化，克服水在工件表面形成非均匀点状接触导致新“微凹坑”不断形成的不足。通过研究KDP晶体在含水介质中的材料去除特性，获得调控抛光介质性能的方法，并揭示氮冷等离子体对KDP晶体刻蚀规律的影响。通过研究KDP晶体在抛光界面上的摩擦特性和KDP晶体表面微观结构、拉曼光谱，以及氮冷等离子体对KDP晶体表面亲水改性的时效性，综合评估氮冷等离子体中的KDP晶体的抛光机理。结果 在抛光过程实验中，证明了氮冷等离子体改性KDP晶体潮解能够提高KDP晶体的表面质量。使用优化的放电参数，表面粗糙度(RMS)从18.4 nm下降至7.6 nm，PV值从109.9 nm下降至61.5 nm。材料去除率最低为10.14 μm/min，最高达91.58 μm/min。结论 利用氮冷等离子体，可快速、无损地将KDP晶体表面处理至超亲水状态，能有效去除液滴驻留产生的微凹坑，表面质量大幅提升，划痕明显减少，实现了液膜接触潮解抛光，为KDP晶体高质高效抛光提供新的思路。

KDP crystal was modified by nitrogen cold plasma to achieve high quality and high efficiency liquid film contact deliquescence polishing. Using nitrogen cold plasma to process the deliquescence polishing interface in real time, the droplet in micro vapor mist changed from droplet residence to liquid film contact on KDP crystal surface, which overcame the shortage of continuous formation of new “micro pits” caused by uneven point contact of water on the workpiece surface. By studying the material removal characteristics of KDP crystal in aqueous medium, the method to control the performance of polishing medium was obtained, and the mechanism of nitrogen cold plasma affecting the etching law of KDP crystal was revealed. The polishing mechanism of KDP crystal by nitrogen cold plasma was comprehensively evaluated by studying the friction characteristics of KDP crystal in the polishing interface, the microstructure of KDP crystal surface, Raman spectrum and the aging of hydrophilic modification of KDP crystal surface by nitrogen cold plasma. It was proved that the deliquescence of nitrogen cold plasma modified KDP crystal can further improve the surface quality of KDP crystal in the polishing process. Finally, using the optimized discharge parameters, the RMS value of the surface roughness decreased from 18.4 nm to 7.6 nm, and the PV value decreased from 109.9 nm to 61.5 nm. The lowest material removal rate was 10.14 μm/min and the highest was 91.58 μm/min. The conclusion is that using nitrogen cold plasma, KDP crystal can be quickly and non destructively treated to superhydrophilic state, which can effectively remove the micro pits caused by droplet residence, greatly improve the surface quality and reduce the scratch, providing a new idea for high quality and efficient polishing of KDP crystal.