Detailed　studies　on　the　ablation　threshold　of　Mo　with　picosecond　laser　pulses　are　reported　in　this　paper.　The　laser　pulses　used　for　the　research　were　1064　nm　in　wave　length　and　15　ps　in　pulse　duration.　Scanning　electronic　microscope　(SEM)　and　optical　surface　analyzer　were　used　to　analyze　the　ablation　sample,　and　by　analyzing　the　linear　relationship　between　the　squared　diameter　of　ablation　crater　and　pulses　energy　we　obtained　the　ablation　threshold　of　Mo　with　single-　and　multi-pulses.　Influence　factors　of　ablation　threshold　were　observed　while　analyzing　machining　process.　Finally,　the　shape　and　topography　of　holes　drilled　by　percussion　with　ablation　regularity　in　Mo　were　studied,　which　provided　an　important　guidance　for　the　following　applications　on　picosecond　micro-machining.