This　study　aims　to　enhance　the　localized　energy　of　the　plasma　arc　to　meet　the　requirement　of　thick　metal　plate　welding.　To　achieve　this,　a　novel　hybrid　heat　source　by　coaxial　arranging　the　laser　and　plasma　arc　was　proposed,　named　laser-enhanced　plasma　arc　(LPA).　This　special　torch　combines　the　two　kind　sources　by　a　tubular　tungsten　electrode　which　the　laser　passes　through,　use　laser　to　heat　localized　plasma　arc　to　modify　the　energy　distribution.　The　three-dimensional　temperature　field　was　measured　to　clarify　the　effect　of　laser　on　plasma　arc　energy　distribution　and　the　absorption　characteristics　of　laser　by　plasma　arc.　The　numerical　simulation　model　was　established　to　reveal　the　influence　mechanism.　Results　show　that　there　is　a　high　laser　absorption　region　in　the　plasma　arc,　and　it　exists　obvious　effects　of　plasma　arc　pressure　and　temperature　on　laser　absorption　rate.　The　location　and　size　of　the　high　laser　absorption　region　change　as　the　welding　parameters　because　the　temperature　and　pressure　of　plasma　arc　change.　The　results　also　substantiate　that　the　hybrid　source　energy　can　be　adjusted　locally　to　increase　the　effective　flame　length　of　the　plasma　arc　by　changing　the　laser　energy　and　plasma　arc　parameters,　which　is　beneficial　for　thick　metal　plate　welding.　This　study　aims　to　enhance　the　localized　energy　of　the　plasma　arc　to　meet　the　requirement　of　thick　metal　plate　welding.　To　achieve　this,　a　novel　hybrid　heat　source　by　coaxial　arranging　the　laser　and　plasma　arc　was　proposed,　named　laser-enhanced　plasma　arc　(LPA).　This　special　torch　combines　the　two　kind　sources　by　a　tubular　tungsten　electrode　which　the　laser　passes　through,　use　laser　to　heat　localized　plasma　arc　to　modify　the　energy　distribution.　The　three-dimensional　temperature　field　was　measured　to　clarify　the　effect　of　laser　on　plasma　arc　energy　distribution　and　the　absorption　characteristics　of　laser　by　plasma　arc.　The　numerical　simulation　model　was　established　to　reveal　the　influence　mechanism.　Results　show　that　there　is　a　high　laser　absorption　region　in　the　plasma　arc,　and　it　exists　obvious　effects　of　plasma　arc　pressure　and　temperature　on　laser　absorption　rate.　The　location　and　size　of　the　high　laser　absorption　region　change　as　the　welding　parameters　because　the　temperature　and　pressure　of　plasma　arc　change.　The　results　also　substantiate　that　the　hybrid　source　energy　can　be　adjusted　locally　to　increase　the　effective　flame　length　of　the　plasma　arc　by　changing　the　laser　energy　and　plasma　arc　parameters,　which　is　beneficial　for　thick　metal　plate　welding.