To solve the problem that a large number of silt bulges at the head of the deep soft foundation and affects the bottom falling effect at the embankment gap，we carry out an analysis and research on the closure method of the embankment gap. Based on the Yushan south embankment project，we firstly analyze the charging technology of blasting compaction and measure the thickness of silt bulge，and then determine the width of the embankment gap according to the flow velocity. Finally，the embankment structure at the gap is formed by setting a temporary dam and blasting several times to both sides of the dam. The drilling test results show that the quality of blasting compaction and bottom falling at the embankment gap is good，and the closure method can meet the requirements of the design section.