About the problem of total uplift force on platform in front of straight wall，this paper studies the spatial and temporal distribution characteristics and the statistical distribution of total uplift peak value under the action of irregular waves by using physical model test，and analyzes the relationship of the factors of wave height，relative wavelength，relative platform width，relative superelevation with total uplift force. The results show that，when Δh/Hs＞-0.5，the maximum total uplift force and the maximum impact pressure occur at the same time.The statistical distribution of total uplift peak value conforms to the three parameters Weibull distribution. The change of total uplift force with relative superelevation is approximately normal distribution，and extreme value occurs near Δh/Hs=0.2. It is suggested that in engineering design，the bottom of the platform should be arranged in the position of half wave height below the water surface rather than near the static water surface.