Cadmium zinc telluride (CdZnTe) is the most critical room-temperature semiconductor nuclear radiation detector material. A portion of Te was substituted by Se in the CdZnTe lattice to obtain cadmium zinc telluride selenide (CdZnTeSe); this led to an increased composition of the ionic bonds in the lattice, which improved the hardness of the crystal and reduced the concentration of Cd vacancies and Te inclusion defects, thereby enhancing the quality of the material. In this study, to obtain CdZnTeSe crystals suitable for the manufacture of nuclear radiation detectors, the growth of CdZnTeSe crystals under Te-rich conditions was investigated using the vertical Bridgman method, and Cd0.9Zn0.1Te0.97Se0.03 single-crystal ingots with a diameter of 21mm and a length of more than 70mm were successfully prepared. The Cd0.9Zn0.1Te0.97Se0.03 crystals thus obtained had an X-ray diffraction wobble half-peak width of 0.104° in the (110) plane, and the size of the Te intercalation phase was ＜5μm, indicating that the crystals had good crystallinity. The energy bandgap and infrared (IR) transmittance of the Cd0.9Zn0.1Te0.97Se0.03 ingot tails were lower than those of the head and middle of the ingot. This can be attributed to the decrease in crystallinity in the subsequent growth stages of the crystals due to the insufficient release of latent heat during the growth of Cd0.9Zn0.1Te0.97Se0.03 using the vertical Bridgman method. The electrical performance indices of the head and middle of the CdZnTeSe ingots satisfied the requirements for the preparation of room-temperature radiation detectors.