We propose a finite-difference time-domain algorithm in a rotating reference frame to facilitate systematic study of Sagnac effect in photonic devices. Through the design of software simulation on a cluster system platform, the relation between Sagnac phase shift and distance in different rotation systems and the stability of finite-difference time-domain algorithm are verified. The experimental results show that the algorithm is capable of modeling the Sagnac effect effectively, and can be used for various devices with complicated geometry and material properties in the rotating reference performance evaluation system.