There are few studies on the mineralogical characteristics, spectral characteristics and the cause of color of the Smithsonite jade which appears to take on various hues, such as yellow, blue, pink, green, etc. In this paper, yellow-green smithsonite samples were selected and determined by X-ray powder diffractometer (XRD), electron probe (EPMA), laser denudation inductively coupled plasma mass spectrometer (LA-ICP-MS), Fourier infrared transform spectrometer (FTIR), Raman spectrometer (Raman), UV-Vis spectrophotometer (UV-Vis), electron paramagnetic resonance spectrometer (EPR). XRD test results show that the main component of the sample is smithsonite. EPMA test result shows that the main composition of smithsonite is ZnO, with an average content of 61.3%, and the secondary components are CaO, FeO, MnO, CdO and PbO. LA-ICP-MS test result shows that the content of transition elements Fe and Mn in the samples was relatively high, with an average content of 7 363×10^-6 and 3 558×10^-6, respectively. FTIR spectroscopy analysis showed that there are characteristic peaks of smithsonite, namely 740, 883, 1 490 cm^-1, which are caused by in-plane bending vibration, out-of-plane bending vibration and antisymmetric stretching vibration $CO_{3}^{2-}$. The calcite Raman characteristic shifts of 300, 728, 1 091 cm^-1 were shown in every sample caused by the symmetric stretching vibration of ZnO, in-plane bending vibration and symmetric stretching vibration of C$CO_{3}^{2-}$. UV-Vis tests show that the absorption bands around 377, 395 and 417 nm are caused by the ⁶A₁→⁴E(D), ⁶A₁→⁴T₂(D) transition of Fe³⁺, and d—d transition Mn²⁺ were responsible for the yellow-green color of the samples. The EPR spectrum also shows the characteristic six-fold hyper-fine resonance lines of Mn²⁺ at g=2.0 and Fe³⁺ at g=1.98. Combined with the results above, it is believed that the yellow-green color of the diamond is caused by the electron transition of Fe³⁺ and Mn²⁺d—d orbitals.