Cr3+ doped Zn3Ga2Ge2O10∶Cr3+ far-red phosphor was synthesized by the high temperature solid state method, and the luminescent properties of Zn3Ga2Ge2O10∶Cr3+ was tuned by introducing In3+. The crystal structure of Zn3(Ga1-xInx)2Ge2O10∶2%Cr3+ was determined by X-ray diffraction(XRD), and the luminescent properties were analysed using room-temperature photoluminescence spectra and thermoluminescence spectra. Zn3(Ga1-xInx)2Ge2O10∶2%Cr3+ exhibits a broad emission band, which is composed of two luminescent peaks at 705 and 721 nm from the transitions of 4T2(4F)→4A2 and 2E→4A2 respectively. As the In3+ doping concentration increases, the emission spectrum of Zn3(Ga1-xInx)2Ge2O10∶2%Cr3+ broadens. This broadening is attributed to the changes in the crystal field environment around the Cr3+, which leads to an increase in the full width at half maximum (FWHM) of the material's emission spectrum as the crystal field splitting becomes more pronounced. Therefore, Zn3(Ga1-xInx)2Ge2O10∶2%Cr3+ phosphors are expected to be applied in the field of plant lighting for their luminescence characteristics matching with the absorption spectrum of phytochrome in plants. Additionally, as the In3+ doping concentration increases, the phosphor material exhibits a red long afterlow phenomenon, and its afterglow duration is related to the In3+ doping concentration.