\begin{tikzpicture} [scale=1]
      \tkzDefPoint(0,0){A}
      \tkzDefPoint(4,0){B}
      \tkzDefShiftPoint[A](45:1.5){D}
      \tkzDefShiftPoint[B](45:1.5){C}
      \tkzDefShiftPoint[A](90:3){A_1}
      \tkzDefShiftPoint[B](90:3){B_1}
      \tkzDefShiftPoint[C](90:3){C_1}
      \tkzDefShiftPoint[D](90:3){D_1}
      \tkzDefMidPoint(B_1,D_1)\tkzGetPoint{M}
      \tkzDrawSegments[thick,black, , ](A,B B,C A,A_1 B,B_1 C,C_1 A_1,B_1 B_1,C_1 C_1,D_1 D_1,A_1 B_1,D_1)
      \tkzDrawSegments[thick,red,dashed, ](C,D D,A D,D_1 D,M M,C_1 D,B M,B D,C_1)
      \tkzDrawMarks[mark=ball,mark size=1.5pt](A,B,C,D,A_1,B_1,C_1,D_1)
      \tkzLabelPoints[above](A_1,B_1,C_1,D_1)
      \tkzLabelPoints[below](A,B,C,D)
\end{tikzpicture}

找点直接连吧，简单粗暴！

\begin{tikzpicture}
  \tkzInit[xmin=-2,xmax=2,ymin=-2,ymax=2]
  \tkzDrawX[black,thick,noticks , ]
  \tkzDrawY[black,thick,noticks , ]
  \node at (-0.2,-0.2){$O$};   
  \tkzDefPoints{-1.76/1.99/A,-1.33/0.52/B,-0.76/1.63/C,0/-1.18/D,0.82/1.63/E,1.39/0.49/F,1.84/1.97/G}
  \draw[blue] plot[smooth,samples=500,tension=0.9] coordinates{(A)(B)(C)(D)(E)(F)(G)};
\end{tikzpicture}