A novel 84 kWe high flux solar simulator with six instantaneous switch gates is designed in this study. Based on the indirect measurement method, a data acquisition and control software for the flux measurement is developed. A flux measurement algorithm is accomplished based on image processing method. In order to reduce random error, the least squares method is used to fit the average radiative flux and the average gray value. Then, the indirect flux measurement error is analyzed. The total errors of radiative flux and total radiative power for high flux solar simulator with all lamps in operation are ±10.57% and ±10.63%, respectively. The radiative flux mappings of solar simulator at different planes are obtained. The experimental results show that the radiative flux mapping is consistent with the ellipsoidal Gaussian distribution. The maximum system efficiency of 84 kWe high flux solar simulator is 38.1%. The maximum peak flux is 9.3 MW/m2 at the focal plane. The maximum average radiative flux on 5 cm diameter target is 5.2 MW/m2 at +1 cm plane. For a single short-arc xenon lamp, the maximum of peak flux, radiative power and system efficiency reach 1.2 MW/m2, 2.88 kW, and 41.1%, respectively.