Abstract: Bimetallic thiocyanate crystal materials: zinc cadmium thiocyanate(ZCTC)is potentially useful in second harmonic generation(SHG). A large typical single crystal with dimensions up to 28mm × 10mm × 8mm was obtained by slow solvent-evaporation method. The transmission properties of KSCN and ZCTC in solution state and two transmission directions of the ZCTC crystal were discussed, the results show that SCN^- is the main affecting factor of the UV cut-off wavelength of ZCTC crystal and the transparency of (100) plane is higher than（001）plane. Chemical coating is an effective method of reducing the surface reflection loss of ZCTC crystal. ZCTC crystal was kept in the oven about 180℃ for 24h, and the transparency of ZCTC crystal is declined between 300-800nm.