Abstract: This paper conducted a damage investigation on the micro epicenter of the Yangbi M_s6.4 earthquake on May 21, 2021. Based on the observation data of mobile observation topographic array, the influence of topographic effect on ground motion characteristics is analyzed. It is found that if the seismic wave is incident perpendicular to the mountain trend, the steep slope will amplify the high-frequency part of the seismic wave, and there are obvious differences in the low-frequency part of Fourier amplitude spectrum along the mountain trend and vertical at different elevations. The site component(k₀) of high-frequency attenuation parameters is calculated by spectral attenuation method, then the relationship between the horizontal component of k₀, the vertical component of k₀, the ratio of horizontal to vertical component of k₀ and station elevation, site weakness and dominant frequency is analyzed respectively. The results show that for micro and small earthquakes within a near distance (<30 km), the horizontal component of k₀ is not affected by the dominant frequency and elevation changes, but to which the vertical component of k₀ is sensitive to; The soft the site, the larger the horizontal component of k₀, while the variation of the vertical component of k₀ is not obvious.