In response to the demand for high-quality CdZnTe single crystal materials in the preparation of far-infrared detector substrates，a distributed zone melting and purifying furnace composed of zone melting furnace body, moving heating device, gas circuit system and electrical control system for preparing material of CdZnTe crystals is designed based on the principle and process realization method of zone melting purification in order to meet the need of high-purity raw materials for the growth of highquality CdZnTe single crystals. The zone melting purification furnace is realized by the method of hydrogen impurity removal, nitrogen protection and servo mechanism to control the movement of the heating temperature field. The zonal purification experiments of tellurium, zinc and cadmium are carried out under the condition that the zonal narrow zone width is 15 mm and the incline angle is 7°. The results show that when the heating temperature is 50 K higher than the melting point and the moving speed is 0.006 mm·s^-1, the purity of the raw material for CdZnTe crystal preparation can be increased from 6N (99.9999%) to 7N (99.99999%) if the zonemelting heating device moves more than 10 times. The heating temperature, the moving speed of the heating device and the moving stability of this furnace are better.