Pulse repetition interval (PRI) selection significantly impacts the performance of modern radar systems. Although fixed PRI radar systems have made significant advancements, they face inherent challenges such as vulnerability to interference, deception, and high sidelobe levels. To mitigate these issues, random PRI radar systems have been developed, offering improved multitarget detection and enhanced anti-jamming capabilities. However, random PRI introduces complexity in sidelobe suppression, which is critical for maintaining radar system performance. This paper reviews sidelobe suppression techniques in random PRI radar, focusing on the Cyclic Algorithm-New (CAN) and various window functions, including Hanning, Hamming, Kaiser, and Chebyshev windows. By leveraging the CAN algorithm’s unique capability to optimize phase in the frequency domain, this study transfers the traditional trade-off between main lobe width and sidelobe suppression to edge effects. The results demonstrate that applying time-domain windowing to the time-domain sequence (which was optimized in the frequency domain via the CAN algorithm) significantly improves sidelobe suppression, with the Chebyshev window showing superior performance in high-precision scenarios. This work provides a solid theoretical and practical foundation for enhancing radar system performance in complex electromagnetic environments.