Based on the research and optimization analysis on the drilling mechanism and cutting structure of the rotary drilling bucket, according to the problems in the rotary drilling process, such as low drilling efficiency; poor guidance of centering tip and being easy to slip; ineffective residual soil collection; outer edge teeth holder wearing and the tips of outer edge teeth being easy to break; much sediment at the hole bottom and wall and the structure type of the soil leading plates can not meet the engineering requirements, the structural design of centering tip and soil leading plates are optimized and improved, as well as the cutting teeth distribution, teeth quantity and the rock cracking angle. By the optimized improvement, the drilling efficiency is improved by 80%. In addition, the labor intensity is alleviated, the bit service life is extended and the construction cost is reduced, the practice provides the theoretical basis and experience for the structure design and application of the rotary drilling bucket in the future.