To adapt to the development trend of combining high precision fiber time-frequency transfer with optical fiber communication network, the time-frequency transfer performance of wavelength selection switch (WSS) which is commonly used in optical fiber communication network is studied. A system with high precision fiber time-frequency transfer is established based on the wavelength division multiplexing, bidirectional return and optical real time delay compensation scheme. The effects of output ports, output loss and variation of polarization state of input optical signal on the time-frequency transfer performance of the system are discussed. In addition, the open-loop and closed-loop performance of time-frequency transfer system including WSS and the influence of dynamic switching performance of WSS under closed-loop on the time-frequency transfer system are studied. The experimental results show that the effect of WSS on the fiber time-frequency transfer performance can be controlled, and it is proved that the high precision time-frequency transfer in the commercial optical fiber communication network with WSS is feasible.