Abstract: The γ ray total absorption BaF₂ detector facility is being constructed at China Institute of Atomic Energy, which will be used to accurately measure the neutron capture cross section with the energy of keV. The pulse signals from the detectors were acquired by FlashADC. The energy spectra of ⁶⁰Co and ¹³⁷Cs were obtained by integral of waveform area, and their resolutions were as equal as that of traditional electronics method. Three methods （pulse shape discrimination, baseline compensation and time window limit） of digital waveform analysis were applied to effectively reduce the background from α particles and electronics noise. The arrival time of γ ray detected by BaF₂ detector was determined by various timing methods. The comparison of FWHM indicates that constant fraction discrimination and digital constant fraction discrimination will be used to measure the neutron energy of capture reaction in online experiment.