The results of numerical simulation were compared respectively with and without considering the improved coefficient for the energy transfer process in ErP5O14 noncrystalline under 521.8, 450.0, 405.5 and 378.5 nm lights excitation. The results showed that it is essential to take the coefficient into calculation where energy transfer plays a key role. The relative fluorescence intensity ratios of 4I13/2→4I15/2 to 4I11/2→4I15/2 under 523.8, 450.0 and 378.5 nm lights excitation were 2.11, 2.82 and 2.99 times larger than that under 979.3nm light excitation respectively. There are obviously effective near-infrared (NIR) quantum cutting of 4I13/2→4I15/2 transition. The result indicates that ErP5O14 noncrystalline has potential application in the enhancement of conversion efficiency of germanium solar cells.