Over　the　past　decade　researchers　had　demonstrated　much　interest　in　laser　clad　TiB2　composite　coating　for　its　good　wear　resistance,　corrosion　resistance　and　high　temperature　properties;　however,　the　surface　depression　of　TiB2　composite　coating　was　obvious.　In　this　paper　the　flow　behaviour　of　the　molten　pool　was　observed　by　the　high-speed　camera.　The　formation　process　of　the　coating　depression　was　analysed　and　the　suppression　methods　of　the　coating　depression　were　also　studied.　The　results　showed　that　the　depression　formation　of　the　coating　undergoes　three　stages:　downward　deposition　of　particles;　the　molten　liquid　flows　into　the　low　temperature　region;　and　rapid　solidification　process.　The　depression　of　the　coating　can　be　improved　by　pre-heating　and　laser　track　overlapping.　These　two　measures　were　helpful　to　improve　the　fluidity　and　the　amount　of　the　molten　liquid.　Meanwhile,　the　depression　degree　of　the　coating　can　be　gradually　reduced　with　the　increasing　scanning　speed.