A　kind　of　SiGe　heterojunction　phototransistor　with　gradual　coupled　ridge　waveguide　based　on　silicon-on-insulator　(SOI　SiGe　GRC　HPT)　is　designed　and　optimized　to　improve　its　optical　responsivity　and　working　speed.　When　the　width　and　length　of　the　ridge　waveguide　are　optimized　as　3um　and　20um　separately,　the　ridge　waveguide　based　on　SOI　provide　the　same　limitation　for　TE　mode　and　TM　mode　and　the　suitable　propagation　path　for　incident　light.　The　maximum　characteristic　frequency　of　SOI　SiGe　GRC　HPT　is　102GHz,　its　saturation　current　is　20mA　and　its　optical　responsivity　is　0.5　A/W.　©　2020　IEEE.