In　this　paper,　high　power　fiber　laser　and　DC　TIG　welding　machine　were　used　to　carry　out　hybrid　welding　experiments.　The　influence　of　heat　source　relative　position　on　welding　process　was　studied　from　the　aspects　of　weld　surface　forming,　porosity,　weld　depth/weld　width　and　dynamic　behavior　of　molten　pool/keyhole.　The　results　showed　that　compared　with　the　laser-guided　welding,　the　weld　surface　roughness　and　contour　height　were　higher,　the　mass　loss　of　plate　was　smaller　during　the　arc-guided　welding.　Compared　with　the　arc-guided　welding,　the　greater　weld　depth　and　the　smaller　weld　width　can　be　achieved　when　laser-guided.　The　different　heat　source　arrangement　will　significantly　affect　the　laser　absorption　of　the　plate,　the　angle　of　the　front　keyhole　wall　and　the　state　of　the　plasma,　so　as　to　affect　the　weld　depth　and　weld　width.　The　maximum　difference　of　weld　depth　between　different　arrangements　of　heat　sources　was　about　20%.　Further　analysis　showed　that　molten　pool　bulge　near　the　front　and　back　of　the　keyhole　mouth　were　acted　by　the　arc　force　along　the　welding　direction,　and　the　influence　of　this　force　on　the　liquid　column　was　the　main　reason　for　the　change　of　the　weld　surface　shape　in　the　hybrid　welding　with　different　guidance　modes.