This paper deals with the following fractional Kirchhoff problems: ( ε 2 s a + ε 4 s − N b ∫ R N | ( − Δ ) s 2 u | 2 d x ) ( − Δ ) s u + V ( x ) u = | u | 2 s ∗ − 2 u , in R N , where a, b>0, s ∈ ( 0 , 1 ) , 2s<N<4s, ε is a positive parameter, 2 s ∗ = 2 N N − 2 s is the critical Sobolev exponent, V ( x ) ∈ L N 2 s ( R N ) and V ( x ) vanishes at some points in R N . In virtue of a global compactness result and Ljusternik–Schnirelman theory, we succeed in proving the multiplicity of bound states.