Abstract: The composite / metal hybrid structure is widely used in composite cylinders of new energy vehicles, which has different impact damage characteristics compared with pure composite structure． This paper,combining both the tests of composite cylinder and test panel,evaluates impact resistance performance with parameters such as: impact energy absorption rate,delamination extension resistance and attenuation factor of the residual strength ratio． The experiments of falling ball impact with various support fixtures and glass fiber /epoxy unidirectional laminates are carried out to simulate how different liner materials of composite cylinders affect the impact damage degree of fiber winding layers． It is found that,under certain impact energy,changing composite / metal hybrid structure leads to the change of impact energy absorption rate and increases critical value of impact damage,namely,bear load impact capacity． The higher impact energy absorption rate will reduce delamination extension resistance,and the residual strength of laminate with impact damage will attenuate faster． As a result,the effect of delamination extension resistance and impact energy absorption rate should be taken into consideration while designing composite cylinders．

Key words: composite cylinders, impact resistance, evaluation parameters