Special Lie-Mei symmetry and conserved quantities for Appell equations expressed by Appell functions in a holonomic mechanical system are investigated. On the basis of the Appell equation in a holonomic system, the definition and the criterion of special Lie-Mei symmetry of Appell equations expressed by Appell functions are given. The expressions of the determining equation of special Lie-Mei symmetry of Appell equations expressed by Appell functions, Hojman conserved quantity and Mei conserved quantity deduced from special Lie-Mei symmetry in a holonomic mechanical system are gained. An example is given to illustrate the application of the results.