A new high-yielding hybrid rice combination called Tianyou 673 was developed using space mutation and crossbreeding technology. It was created by crossing a good quality CMS line with a restorer line, resulting in a variety with strong restoring ability, wide adaptability, and resistance to rice blast. Tianyou 673 outperformed other main cultivars in terms of yield, grain quality, and disease resistance. In trials, it yielded 5.39% higher than the check hybrid Shanyou 63, and in production tests, it yielded 10.29% higher. This new hybrid rice variety was officially released for commercial use in Fujian Province in 2010. The method of combining space mutation with crossbreeding technology has proven effective in developing high-yielding and disease-resistant hybrid rice varieties.