Abstract: In order to measure high intensity femtosecond laser with single-shot precisely in real-time, a real-time measurement system was designed via processing data from a single-shot autocorrelator with LabVIEW. The precision is highly improved with signal noise decreased by limiting image processing area and integrating the image data. The autocorrelator was calibrated on-line by means of self-calibration, and pulse duration was obtained in real time. The precision of 3.6fs per pixel was obtained with small-pixel-size CCD. Ti:sapphire laser with pulsewidth of 50fs and center wavelength of 800nm was measured in real-time with our developed device. The results prove that femtosecond pulses can be measured precisely in real-time with a single-shot autocorrelator based on LabVIEW.