: The determination of radioiodine remnant ablation (RRA) dosage in post-operation thyroid residual tissues resection has been largely subject of discussion, yet no concise conclusion is released through systematic review studies. In this study, we conducted a systematic review of comparative experiments to evaluate and compare the efficacy of different prescribed dosages of radioiodine in post-op thyroid residual tissues resection among low, intermediate, and high-risk patients to approve the common method. Using automated searches, studies were collected from PUBMED, GOOGLE SCHOLAR, ELSEVIER, SCOPUS, and UPTODATE, all until April 2021. Alongside the aforementioned sources, comparative experiments were added in for further investigation. Overall, 4000 patients with papillary thyroid cancer, differentiated thyroid carcinoma (DTC), metastasized and non-metastasized thyroid cancer took part in twenty-one trials are assessed. We discovered no significant difference in successful thyroid residual tissues excision between low-activity and high-activity radioiodine treatment in people with low and intermediate risk. In these individuals, there was no significant difference between the high therapeutic dose of 3700 MBq and the lesser dose of 1850 MBq for RRA. However, high-dose treatment usually yielded superior results. Low activity RRA causes fewer adverse effects in metastasis-free patients than high-activity 3.7 GBq. There was no significant therapeutic difference regarding treatment efficacy in patients with low and moderate risks. However, in patients with high-risk status, applying a high-dose regimen of RRA produced a significantly better response.