The UV system contains prepolymer, monomer and photoinitiator has been broadly used in printing area. UV-curable inkjet ink with its environmental protection, energy-saving, good printing quality and high efficiency has become the most concerned topic and has a good development prospects. The use of UV ink-jet printing ink in ink-jet digital printing is the main development trend of digital printing currently and a period of time in future. Curing rate is one of the most important performance parameters of the UV system which is greatly affected by prepolymer, monomer and photo-initiator, besides that, the oxygen atmosphere is another principal element. In order to investigate the influence of different oxygen atmosphere on the curing reaction, we designed and made a UV curing device with varied degree of oxygen atmosphere to study the effect of photo-initiator species and content on the systems curing rate under different oxygen atmosphere condition.