Numerical　simulation　methods　were　adopted　to　investigate　the　heat　transfer　and　film　cooling　effect　at　the　pressure-side　winglet-squealer　tip　in　the　first　stage　of　a　gas　turbine.　The　effects　of　seven　different　tip　geometries　(e.g.uniform　cross-section　winglet　and　distortion　winglet)　on　the　aerodynamic　performance　of　turbine　stage　and　the　heat　transfer　coefficient　distributions　at　the　tip　were　analyzed.　The　film　cooling　and　heat　transfer　performances　at　the　conventional　squealer　tip,　non-pressure-side　rim　tip　and　pressure-side　winglet　tip　with　two　different　hole　arrangements　(single　row　of　hole-array　and　double　rows　of　hole-array)　were　compared.　The　result　shows　that　a　high　heat　transfer　area　appears　on　the　cavity　floor　of　the　conventional　squealer　tip.　A　proper　design　of　pressure-side　winglet　is　able　to　effectively　eliminate　the　high　heat　transfer　area　on　the　cavity　floor　and　also　reduce　the　averaged　heat　transfer　coefficient　at　the　squealer　tip.　Compared　with　the　conventional　squealer　tip,　the　averaged　heat　transfer　coefficient　at　the　distorted　winglet　tip　with　round　corners　is　reduced　by　about　16.45%.　The　single　row　of　tip　cooling　holes　has　a　significant　effect　on　reducing　the　averaged　heat　transfer　coefficient　of　squealer　tips,　while　the　film　cooling　effectiveness　at　different　squealer　tips　is　significantly　improved　with　the　double　rows　of　hole-arrays.　For　the　single　row　of　hole-array　cases,　the　advantage　of　film　cooling　effect　on　the　winglet-squealer　tip　is　not　obvious.　The　heat　transfer　and　film　cooling　effect　can　be　improved　significantly　by　adding　film　cooling　holes　at　the　blade　pressure　side.　With　both　tip　and　pressure-side　cooling　hole-arrays,　the　averaged　heat　transfer　coefficient　at　the　winglet-squealer　tip　is　about　0.76%　lower　than　that　of　the　conventional　squealer　tip,　and　7.84%　lower　than　that　of　non-pressure　side　rim　tip.　The　film　cooling　effectiveness　at　the　winglet-squealer　tip　is　about　9.13%　higher　than　that　of　the　conventional　squealer　tip,　and　9.6%　higher　than　that　of　the　non-pressure　side　rim　tip.　©　2022,　Editorial　Office　of　Journal　of　Xi＇an　Jiaotong　University.　All　right　reserved.