Quantum computing has unparalleled advantages over classical computers in solving certain problems, but the inherent fragility of quantum systems makes the implementation of quantum computing difficult. Simulating quantum computing based on stable classical optical systems can effectively avoid the difficulties faced by quantum systems and has important research value. Based on the existing optical simulation theory, this paper designs CNOT gates using the path and polarization degrees of freedom of the optical field, and uses the combination of CNOT gates to realize the SWAP gate; The optical paths of Hadamard gate and controlled S-gate are designed, and combined SWAP gate to realize a two-bit quantum Fourier transform algorithm. Compared with quantum systems, the scheme proposed in this paper has a simple device and easy operation, significantly reducing the difficulty and cost of implementation, providing interesting possibilities and approaches for quantum computing.