Studying the effect of biaxial strain on the electronic and optical properties of single-layer CdZnTe semiconductor materials provide theoretical support for the preparation of CdZnTe devices with excellent optical properties. In this paper, a single-layer CdZnTe model was built with the Material Studio software, and strain is applied to the model in the (100) and (010) directions. Based on the first-principle of density functional theory, the effects of biaxial strain on the band gap, effective mass of carrier, mobility and dielectric constant of single-layer CdZnTe were simulated and calculated. The results show that both tensile and compressive strains reduce the band gap of the single-layer CdZnTe, and biaxial strain effectively control the effective mass, mobility and dielectric constant of carriers. Compared with the tensile strain, compression strain of the same size has more obvious effect on the properties of the single-layer CdZnTe. With the increase of applied biaxial compression strain, the band gap of the single-layer CdZnTe gradually decreases, which leds to the increase of wavelength range of absorption light of the CdZnTe semiconductor， and the carrier effective mass and mobility of single-layer CdZnTe show an overall downward trend. Also, the increase of applied biaxial compression strain makes the real part of the dielectric constant gradually decrease and the imaginary part of the dielectric constant gradually increase, which enhances the metallicity of the single layer CdZnTe and improves its optical performance.