The Chirp transform spectrometer(CTS) designed using surface acoustic wave(SAW) technology has the advantages of low power consumption and high stability,and is especially suitable for the field of deep space exploration, This paper proposes a large bandwidth CTS system, A 2 GHz bandwidth Chirp signal is generated by DAC and frequency multiplier,and its dispersion characteristics match those of a 1 GHz SAW delay line, A spectrum analyzer with a real-time processing bandwidth of 1 GHz and a frequency resolution of 100 kHz is built, and the unbalanced response of the CTS under large bandwidth is discussed, The influence of each part of the system on the CTS system is analyzed,and the reasons for the unbalanced response are verified through experiments, The test results show that the designed and built CTS system with a bandwidth of 1 GHz can reach a frequency resolution of 115, 512 kHz,