目的 为了提高包装机械动力机的使用寿命。方法 考虑到包装机械动力机工作外界环境因素的影响以及自身内部衰退规律，引入环境因子和调整因子，在综合内外因素衰退演化规则的基础上，建立以稳态可用度和平均成本率为目标的多目标优化决策模型，并且分析不同环境工况对预防维护时间间隔的影响，再根据最优预防维护时间间隔进行动态预防维护策略研究。结果 研究数值算例表明，衰退演化规则是合理的，且恶劣的环境会加速机械动力机的衰退，急剧缩短预防维护时间间隔。结论 考虑环境因素的影响对机械动力机维护具有实际意义，为其提供良好的工作环境，对提高其稳态可用度和降低维护平均成本率是非常重要的。

The work aims to improve the service life of packaging machinery power machine. The environmental factor and adjustment factor were introduced due to the influence of external environmental factors and the internal recession on the work of packaging machinery power machines. Based on the recession evolution rules of internal and external factors, a multi-objective optimization decision model with steady-state availability and average cost rate as goal was established. The effects of different environmental conditions on preventive maintenance intervals were analyzed. Then the strategy of dynamic prevention and maintenance was studied based on optimal preventive maintenance intervals. The numerical example showed that the recession evolution rules were reasonable, and the harsh environment accelerated the decline of the equipment and drastically reduced the preventive maintenance interval. Considering the influence of environmental factors has practical significance for the maintenance of equipment. It is important for improving the steady availability of equipment and reducing the maintenance average cost rate to provide a good working environment for the equipment.