解：∵??$∠ACB=90°，$????$BC=2，$????$∠A=30°$??
∴??$AB=4，$????$AC=2\sqrt 3$??
如圖，過點??$C$??作??$CH⊥PP'$??于點??$H，$??連接??$PC、$????$P'C$??
∵將??$△ABC$??繞點??$C$??順時針旋轉(zhuǎn)??$120°$??得到??$△A'B'C$??
∴??$∠PCP'=120°，$????$CP=CP'$??
∴??$∠CPP'=30°$??
∵??$CH⊥PP'$??
∴??$CH=\frac 12PC$??
由勾股定理易得??$PH=P'H=\frac {\sqrt 3}2PC$??
∴??$PP'=\sqrt 3PC$??
當(dāng)點??$P$??與點??$A$??重合時，??$CP$??有最大值，即??$PP'$??有最大值，為??$\sqrt 3×2\sqrt 3=6$??
當(dāng)??$PC⊥AB$??時，??$PC$??有最小值，即??$PP'$??有最小值
此時??$PC=\frac {AC · BC}{AB}=\sqrt 3$??
∴??$PP'$??最小值為??$\sqrt 3×\sqrt 3=3$??
∴線段??$PP'$??的最大值為??$6，$??最小值為??$3$??
