Abstract: In order to understand the external load effect affected to the working state of the backfill hydraulic powered support and thus to ensure the operation safety and to prolong the service life of the powered support,the paper introduced the orthogonal test of the virtual prototype.With a ZZC8800/20/38 mode six legs backfill hydraulic powered support as an example,an experiment study was conducted on the stressed influence degree by the external loading effect point location at the rear top beam on the powered support.The results showed that the orthogonal test method could be applied to analyze the performances of the rear canopy on the powered support.The test showed that a torsion loading form would be the danger performances of the powered support,could play a role to reduce the external loading space and could reduce the test times of the reliability test for the late prototype.The test time could be highly reduced.An effective guide method was provided to the danger performance study of the backfill hydraulic powered support,and thus the application and maintenances of the backfill powered support would be favorable.