解:2x2+ax-y+6-2bx2+3x-5y-1=(2-2b)x2+(a+3)x-6y+5 ∵代数式2x2+ax-y+6-2bx2+3x-5y-1的值与字母x的取值无关,∴2-2b=0,a+3=0,∴a=-3,b=1,∴13a3-2b2-14a3+3b2=112a3+b2=112×(-3)3+12=-54.