This　paper　concerns　a　fractional　Kirchhoff　equation　with　critical　nonlinearities　and　a　negative　nonlocal　term.　In　the　case　of　high　perturbations　(large　values　of　alpha,　i.e.,　the　parameter　of　a　subcritical　nonlinearity),　existence　results　are　obtained　by　the　concentration　compactness　principle　together　with　the　mountain　pass　theorem　and　cut-off　technique.　The　multiplicity　of　solutions　are　further　considered　with　the　help　of　the　symmetric　mountain　pass　theorem.　Moreover,　the　nonexistence　and　asymptotic　behavior　of　positive　solutions　are　also　investigated.