In this paper, the undetermined tensor method is used to Birkhoffize the Appell equation for a nonholonomic system. The generating functions are obtained according to the construction principle of generating functions, and then a Birkhoff symplectic scheme is given. Finally, a specific example of Appell equation is provided to verify the above theory and simulate this example. The results show that the preserving algorithm is more effective and superior with the evolution of time.