In order to study transient terahertz radiation from layered ZrTe₅ (zirconium pentatelluride) excited by femtosecond pulses, terahertz time domain system was used to test and analyze the terahertz emission. By analyzing the relationship between terahertz electric field of layered ZrTe₅ and intensity/polarization of femtosecond laser pulse, it was obtained that the main mechanism of terahertz radiation generation by layered ZrTe₅. At the same time, the terahertz radiation intensity of layered ZrTe₅ and intrinsic GaAs (gallium arsenide) under the same pumping conditions was also compared. Studies have shown that the layered ZrTe₅ has narrow band gap structure, shallow absorption depth, larger residual energy of photogenerated electrons and higher carrier mobility, which has better performance than traditional semiconductors in terms of terahertz generation. The experimental research provides a reference for the discovery of efficient and highly integrated terahertz radiation sources.