The 4CzTPN-Ph is mixed into YAG phosphors with the mass concentrations of 1%,1. 3%,2% and 3%,respectively,then the powdering LED device is obtained.The influe nce of doping concentration on light efficiency of the device is researched.Thr ough changing the driving current of the device,the influence of driving conditi ons on light efficiency is researched.Through testing light efficiency change o f LED before and after silica gel filling,the influence of filling on light efficiency is researched.The experimental results show that with the increase of concentration of 4CzTPN-Ph,the light efficiency red uces,but when the concentration increases to a certain extent,the light efficien cy increases conversely.This pape r still find,that with the increase of the current,the light efficiency redu ces,and the light efficiency will increase after silica gel filling.At la st,the reason of the light efficiency change of the device,when the driving cu rrent is increased and after the silica gel is filled with is analysized.