A diluted magnetic semiconductor MnxCd_1-xIn₂Te₄( x =0.1) ingot is grown by ACRT-B method. Using scanning electron microscopy, X-ray powder diffractometer, ISIS energy-dispersive spectroscopy, Leica quantitative optical microscope and Fourier infrared spectrometer, the microstructure, morphology compositional distribution and transmittance properties of the ingot are analyzed. It is found that α, β and β_1 phases are at the tip of the Mn_0.1 Cd_0.9 In₂Te₄ ingot. Among them, α and β phases are formed during the growing process while β_1 is precipitated from α phase when temperature is below solidus. After the ingot is grown for 36mm, only β phase is formed. The morphology of β_1 phase varies from regular plates to irregular near-round blocks along the axis of the ingot from the beginning. The band gap of Mn_0.1 Cd_0.9 In₂Te₄ ingot is 1.2eV. Maximum of its near infrared transmittance in the range of 10000～2500cm -1 is up to 83% and its middle infrared transmittance in the range of 4000~500cm_1 is from 59% to 65%.