Objective The effects of different barycentre position on the life-span of the packaging manipulator were studied, and the life-span of the packaging manipulator was improved in the premise of not changing the packaging robot structure. Methods Using mathematical methods, the horizontal movement of the single freedom packaging robot with load in a linear motion rooling beraing system was calculated and analyzed. Multiple locations in motion mechanism were set for packaging robot with load, and the load barycentre of the positioning was simplified. Through the development of the package Object Oriented Programming C + + program, the rating life-span of multiple locations in the load barycentre of the linear motion rolling guide system with two tracks and four sliders was calculated. Results Based on the locations obtained by calculation, the barycentre of crawling load for the packaging robots was controlled by PLC and the parameters were adjusted. Biasing of load barycentre position for crawling packaging robots was realized. Conclusion Through practical application, the reliability and feasibility of theoretical calculation was verified, and the service life of the packaging robot with load was improved.