The structure parameters, semiconductor characteristics and process morphology of silicon micro-ring resonators have important effects on the output repetition frequency of correlated photon-pair sources. The nonlinear loss of crystalline silicon is included in the simulation calculation of the output repetition frequency, and the spontaneous four-wave mixing effect model of all-pass silicon micro-ring resonators is deduced. Effects of the parameters such as the quality factor of all-pass silicon micro-ring resonators, radius of micro-ring resonators and free carrier life of crystalline silicon on output repetition frequency are investigated by using the model. Results show that when the external quality factor is 5×104, the pumping power reaches 15 mW and continues to increase, the output repetition frequency of the correlated photon-pairs decreases. Ideally, the smaller the radius of the micro-ring resonators is, the higher the output repetition frequency will be. For the silicon micro-ring resonators correlated photon-pair sources, the preferred solution to increase the output repetition frequency is to reduce the free carrier lifetime.