This paper studied the conformal invariance and conserved quantity of the holonomic system, which corresponds to a higherorder nonholonomic system. Firstly, the definition and determining equation of conformal invariance of the system were presented. The conformal factor, which is the necessary and sufficient condition that conformal invariance of the system would be Lie symmetry was deduced from conformal invariance and Lie symmetry. The conformal invariance of weak and strong Lie symmetry for the highorder nonholonomic system was given using restriction equations and additional restriction equations. Secondly, the Noether conserved quantity of conformal invariance of the system was derived. Lastly, an example was given to illustrate the application of the results.