Broken soft coal seams account for a large proportion of coal resources in China， and generally， in-seam drilling is featured of poor hole-forming and shallow drilling depth； while air as a flushing medium of directional drilling process is an effective way to solve the outstanding problems in soft coal seam drilling. In some mining areas， a large amount of condensed water is generated by the flushing medium due to complex working conditions， resulting in extremely low efficiency of in-seam directional drilling， or even difficulty in drilling in broken and soft coal seams. Therefore， from the perspective of underground directional drilling technology for broken soft coal seams， the author analyzes and studies the formation mechanism of condensed water in the air flushing medium under complex working conditions and the influence of condensed water on directional drilling operations in air drilling， and has solved the problem of low drilling efficiency under the complex working conditions by improving the flushing medium channel device. The research results have been verified and applied in a mine in Southwest China. With the improved process， the maximum footage per shift of in-seam directional drilling with the air screw motor reached 51m in soft coal seam with the maximum average drilling rate for a single hole up to 34.5m/shift， which provides an example for in-seam drilling in the similar environment and has important significance for promoting the research on drilling in broken soft coal seam under complex working conditions.