Abstract: In order to study luminescent properties of rare earth ions Yb³⁺ and Er³⁺ with different co-doped molar fractions and ZnF₂ as matrix material, by using high temperature solid state method, samples of rare earth doped by ZnF₂ at 820℃ were prepared and the up-conversion emission spectra was measured. Yb³⁺ and Er³⁺ photon absorption processes were determined by fitting the excitation power and up-conversion power. The results show that under the excitation of 980nm laser diodes, the samples have 3 up-conversion emission peaks of 533nm, 555nm and 655nm in the visible region. The intensity of red light is greater than that of green light.The number of the absorbed photons is 1.73, 1.75, and 1.88. 3 emission peaks are correspond to two-photon absorption.The materials of rare earth ion doped by ZnF₂ have important application prospects in up-conversion red phosphors.