This paper presents a method to detect topological order in a ground state wave function by computing the "topological entropy," which measures the quantum dimension $ D $ of the wave function. Topological order is characterized by a set of data $ (N, d_{i}, F_{lmn}^{ijk}, \delta_{ijk}) $, and the quantum dimension $ D $ is defined as $ D = \sum_{i} d_{i}^{2} $. The paper demonstrates that topological order can be detected by analyzing the entanglement entropy of specific regions in the wave function. The main result is that the topological entropy $ -S_{\text{top}} $ is given by $ -\log(D^{2}) $, where $ D $ is the quantum dimension of the topological field theory associated with the wave function. This quantity is universal and invariant under smooth deformations of the wave function. The paper also provides a physical picture of topological order, emphasizing the presence of nonlocal entanglement in topologically ordered states. The paper discusses the $ Z_{2} $ model as a simple example, where the quantum dimension $ D = 2 $, and the topological entropy is calculated to confirm the result. The general case is analyzed using string-net models, where the wave function is described by a set of data including the number of string types, branching rules, dual string types, and tensors satisfying certain algebraic relations. The ground state wave function is shown to be exactly solvable, and the entanglement entropy is computed for various regions, leading to the general formula for the topological entropy. The paper concludes that topological order is a property of the wave function, not the Hamiltonian, and that the topological entropy provides a universal measure of topological order. The results are supported by references to previous work and are consistent with independent results in the literature.This paper presents a method to detect topological order in a ground state wave function by computing the "topological entropy," which measures the quantum dimension $ D $ of the wave function. Topological order is characterized by a set of data $ (N, d_{i}, F_{lmn}^{ijk}, \delta_{ijk}) $, and the quantum dimension $ D $ is defined as $ D = \sum_{i} d_{i}^{2} $. The paper demonstrates that topological order can be detected by analyzing the entanglement entropy of specific regions in the wave function. The main result is that the topological entropy $ -S_{\text{top}} $ is given by $ -\log(D^{2}) $, where $ D $ is the quantum dimension of the topological field theory associated with the wave function. This quantity is universal and invariant under smooth deformations of the wave function. The paper also provides a physical picture of topological order, emphasizing the presence of nonlocal entanglement in topologically ordered states. The paper discusses the $ Z_{2} $ model as a simple example, where the quantum dimension $ D = 2 $, and the topological entropy is calculated to confirm the result. The general case is analyzed using string-net models, where the wave function is described by a set of data including the number of string types, branching rules, dual string types, and tensors satisfying certain algebraic relations. The ground state wave function is shown to be exactly solvable, and the entanglement entropy is computed for various regions, leading to the general formula for the topological entropy. The paper concludes that topological order is a property of the wave function, not the Hamiltonian, and that the topological entropy provides a universal measure of topological order. The results are supported by references to previous work and are consistent with independent results in the literature.