Abstract: The Ti sapphire femtosecond laser amplification system has the characteristics of low repetition frequency and complex pulse waveform. In order to accurately measure the peak power of the femtosecond laser amplification system, the measurement demand of single pulse waveform and pulse width was proposed. The measurement principle and method of single pulse femtosecond laser time domain waveform and pulse width were introduced, the time domain parameters measuring device of single pulse femtosecond laser based on frequency-resolved optical gating method was designed, and the technical problems and solutions in the calibration of time domain parameters measurement of single pulse femtosecond laser were discussed.