Abstract: Molecular dynamics simulation of indenting and sliding process between a diamond(100) tip and multilayer graphene was accomplished by using two incorporated potential functions with Verlet algorithm. Then the friction force and the average coefficient of friction at different indentation depth were analysed, after that, the number of interlayer bonding, intralayer broken bond and the actual atomic contact area were calculated to elucidate the mechanism for the breakdown of superlubricity. It is shown that the indentation depth had a significant influence on the breakdown of superlubricity, and the amplitude increment of friction force due to a deeper indentation by the tip was similar to that of suspended graphene by a larger compressive strain. The indentation depth of 6.1 Å, was found to be a critical point, the graphene showed an obvious superlubricity when the indentation depth was lower than 6.1 Å, before which the period of Stick-Slip, which is equal to the lattice constant of graphene, hardly changed as indentation depth varied. On the contrary, when the indentation depth was somewhat deeper than 6.1 Å, the friction force versus sliding distance didn’t show a periodic change anymore, and the tip got a much harder potential barrier to overcome, which led to friction force sharply increased and thus the superlubricity evidently broken. It was discovered that the critical depth, at which the interlayer bond/interlayer bond were unprecedentedly formed/broken and increased as indentation depth went deeper, which as a result made the superlubricity broken. The existence of interlayer bond and the broken of intralayer bond were considered to be the main factor causing superlubricity broken and the period of friction force abruptly changed, however, the actual atomic contacting area was hardly relative to phenomenon .