Silicon-based micro-ring resonators (MRRs) are widely used in photonic integration because of their excellent spectral selectivity, compact footprint, and low power consumption. However, MRR wavelength shifts caused by manufacturing errors and the high thermal sensitivity of silicon-based devices can lead to unstable operation. Therefore, a corresponding wavelength-locking scheme must be implemented in practice. In this paper, we propose an MRR wavelength-locking system based on differential evolution and digital perturbation. The output optical power is taken as the monitoring variable, and the optimal heating power is searched for the target signal wavelength based on a differential evolution algorithm in the global search stage. Moreover, the error signal is demodulated based on a digital perturbation algorithm in the local locking stage to increase or decrease the heating power to eliminate the interference of ambient temperature fluctuations. After theoretical derivation and experimental verification, it is found that the proposed differential evolution algorithm is approximately four times faster than the traditional step-by-step scanning method for searching for the optimal heating power. We verify the stable locking of the resonant wavelength of the MRR under a 5 ℃ ambient temperature change within 400 s.