The search for alternative new environmentally insulating gases has become a research hotspot in the fields of chemistry and electrical science since the widespread application of sulfur hexafluoride gas in the power field has brought about increasingly severe environmental pollution. Trans-1,1,1,4,4,4-hexafluoro-2-butene [HFO-1336mzz(E)] gas has been attracted extensive attention at home and abroad due to its excellent environmental characteristics and high dielectric strength. It is necessary to study its spectral absorption characteristics and corresponding detection technology. In this paper, an experimental platform was established, composed of a multi-reflection long optical path cell whose pressure and temperature are adjustable, Fourier transform infrared spectrophotometer (FTIR) and vacuum pumps. Firstly, IR absorption characteristics of HFO-1336mzz(E) in 1 100~1 350 cm^-1 were studied through FTIR experiments and Gaussian simulations at the pressure of 101 kPa and the temperature of 298 K, and the spectral cross-interference analysis of the possible co-existing gases such as CO₂ and H₂O was carried out. The effect of the pressure and temperature of HFO-1336mzz(E) gas on its infrared absorption characteristics was systematically performed. Based on NDIR technology, HFO-1336mzz(E) gas detection of low concentration leakage or high concentration mixing ratio was simulated. From the tested IR absorption spectrum of HFO-1336mzz(E), it can be seen that 1 152, 1 267 and 1 333 cm^-1 are the central wave numbers of the three strong absorption spectra, which is basically in agreement with the simulated IR spectra. When the concentration of HFO-1336mzz(E) is high, the cross-interference of spectral lines of CO₂ and H₂O can be ignored, because the absorption intensity of CO₂ in dry air at 1 333 cm^-1 is as low as 10^-6 and the integrated influence factor of the peak area of H₂O is about 1.44×10^-3 in filter bandwidth of 150 nm. However, humidity compensation is needed when the leakage concentration of HFO-1336mzz(E) is deficient. So, it is feasible to choose the absorption line of 1 333 or 1 267 cm^-1 to realize the detection of low or high concentrations of HFO-1336mzz(E) using NDIR technology. The pressure measured results show that the spectral absorption coefficient of HFO-1336mzz(E) increases with increasing pressure, and its change rates at 1 333 and 1 267 cm^-1 with pressure are respectively 0.273 and 0.118 cm^-1·kPa^-1. However, the width of spectral bands broadens with increasing pressure. The temperature tested results reveal that the peak absorption coefficient of HFO-1336mzz(E) decreases and the width of spectral bands becomes narrow with the increase of temperature, but the change rate of absorption coefficient at different wave numbers is quite different, where the change rates of absorption coefficient at 1 333 and 1 267 cm^-1 are respectively -0.105 6 and -0.035 cm^-1·K^-1. The sensor simulation results indicate that a 5 cm optical path at 1 333 cm^-1 measure a trace leakage of 0~1 800 μL·L^-1, and a 2 mm optical path at 1 267 cm^-1 a high concentration of 0~10% of HFO-1336mzz(E). This research provides an experimental and theoretical basis for developing optical gas sensors based on the principle of infrared spectrum absorption.