本文利用粒子图像测速系统和浪高仪对3种概化岸坡下破碎区至冲泻区的波高、流速等水动力学参数进行实验测量，并基于二阶谱方法分析波高和流速的概率密度分布，统计了破碎区至冲泻区内波高和流速的偏度、不对称度、峰度等高阶非线性变量。结果表明：破碎区至冲泻区内的波高和流速均偏离正态分布，波高偏度和峰度在向近岸传播过程中先减小后增大，不对称度先增大后减小，波高的非线性特征受坡度影响不大。3种工况下流速表现出不同的非线性分布特征，在陡坡和复合坡中，各断面流速偏度分布特征不明显，而在缓坡中各断面流速偏度的垂线分布自床面到自由水面呈现先增大后减小的特征；3种工况下流速的不对称度随距床面距离的增大均呈现先增大后减小的变化趋势。

In this study, Particle Image Velocimetry (PIV) and Wave Gauge (WG) were used to measure the wave height, wave velocity and other hydrodynamic parameters within inner surf and swash zones under three slopes. Based on the second-order spectrum method, the probability density distribution of wave height and velocity between different sections, as well as high-order nonlinear statistical variables such as skewness, asymmetry and kurtosis were analyzed. The results show that the wave height and velocity deviate from the normal distribution, the skewness and kurtosis of wave height decrease first and then increase during the nearshore propagation, the asymmetry increase first and then decrease, and the nonlinear characteristics of wave height are not affected by the slope. The velocity in the three cases shows different nonlinear distribution characteristics. In the steep slope and composite slope, section distribution of velocity skewness characteristics are not obvious. Only the vertical distribution of velocity skewness at each section of gentle slope increases first and then decreases. The velocity asymmetry of the three cases increases first and then decreases with the increase of the distance from the bed.