I just write the code following :
GraphicsRow[{LogLogPlot[{\[Xi]v1[w, 1], \[Xi]v2[w, 1], \[Xi]v3[w, 1]}, {w, 0.01, 1}, PlotStyle -> {Blue, {Black, Dashed}, Black}, PlotRange -> {0.01, 10^4},(*PlotLegends\[Rule]Placed[{"Equation(1)","Equation2", "Numerical"},{{0.02,110},{0.30,110}}],*)ImageSize -> Automatic, Frame -> True, AspectRatio -> 3/2.5], LogLogPlot[{\[Xi]v1[w, 2], \[Xi]v2[w, 2], \[Xi]v3[w, 2]}, {w, 0.01, 1}, PlotStyle -> {Blue, {Black, Dashed}, Black}, PlotRange -> {0.01, 10^4}, ImageSize -> Automatic, Frame -> True, FrameTicks -> {{None, None}, {Automatic, None}}, AspectRatio -> 3/2.5], LogLogPlot[{\[Xi]v1[w, 3], \[Xi]v2[w, 3], \[Xi]v3[w, 3]}, {w, 0.01, 1}, PlotStyle -> {Blue, {Black, Dashed}, Black}, PlotRange -> {0.01, 10^4}, ImageSize -> Automatic, Frame -> True, FrameTicks -> {{None, None}, {Automatic, None}}, AspectRatio -> 3/2.5]}, Spacings -> 0] But I want to achieve the following result: 
It seems "Spacing->0" doesn’t work.These three frames can’t fit closely together.
