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.