Abstract: This paper introduced the Sunda Strait Krakatoa erupting process happened on December 22, 2018 and its monitoring situation, and extract the Esa sentry 1A remote sensing satellite remote sensing image before and after the volcanic eruption, through the contrast analysis of remote sensing images obtained the scope of the collapse of the volcanic cone, we use 3D analysis software module to analyze the DEM image, and calculate the volume of the collapse of the volcanic cone above sea level is about 54 000 000 m³, collapse under the surface of the sea more huge volume, collapse leads to the formation of a volcano happen agitate water waves, The waves' coherent spread to the surrounding coast triggered the sunda strait tsunami. The tsunami disaster mainly occurred in the west coast of Serang county and Pandeglang county in Banten province, Indonesia, which is basically the same as the disaster area that we predicted according to the propagation path of the tsunami caused by the volcanic eruption.