In the maintenance planning of civil aircraft, the initial maintenance tasks based on the MSG-3 standard for civil aircraft are set conservatively due to the lack of usage data support, resulting in problems such as excessive maintenance and poor economy in practice. In response to this situation, this study proposes an optimization method for civil aircraft maintenance tasks based on the guidance of IP 44 and the optimization process of Boeing SASMO. Firstly, sort out the characteristics of obvious operational impact faults based on their impact categories; Secondly, collect all planned and unplanned maintenance data related to this category of maintenance tasks; Then, establish a maintenance event chain to fuse multi-source maintenance data into a failure cycle and conduct statistical analysis, fitting the failure probability curve of the maintenance project; Finally, based on engineering analysis and comprehensive evaluation, output optimization suggestions for maintenance task intervals. The effectiveness of the method has been confirmed through the analysis of airline examples, providing theoretical support for the optimization of such maintenance tasks. The conclusion indicates that the initial maintenance interval decision-making process tends to be conservative, and as aircraft service data accumulates, maintenance tasks should be optimized to reflect actual usage conditions and maintenance needs.