With the rapid development of quantum computing technology, it has entered the noisy intermediate scale quantum (NISQ) era. However, due to the limitations of current technology, a qubit can only be directly interacted with adjacent qubits. In order to implement the logical quantum circuit directly on the NISQ device, it is necessary to insert SWAP gates or use bridge gates to make the qubit nearest neighbor. In order to reduce the number of additional quantum gates inserted in quantum circuit mapping, this paper investigates the dynamic look-ahead based circuit mapping method, considering the impact of inserting SWAP gates in the expansion layer and the cost function model is optimized. Then the best look-ahead depth is determined when inserting SWAP gates through the simulated annealing algorithm, in order to reduce the number of inserted SWAP gates and thereby reduce the number of CNOT gates. The experimental results show that, compared with the existing mapping method, the proposed algorithm can effectively reduce the number of CNOT gates inserted in circuit mapping, and the average optimization rate reaches to 45.59%.