The distributions of the stress, strain and contact stress of the flat type, stiffener type and boss type T profile cylinder head cover gasket were analyzed by using the finite element software.The sealing capability of these types of T profile cylinder head cover gasket was compared. The results show that the sealing capability can be improved by the stiffeners, but different structure types of stiffeners have different effects on the sealing capability, unreasonable designed stiffeners will easily cause the fast failure and aging of T profile cylinder head cover gasket. The flat type gasket is applicable to the condition of long sealing time but not too high sealing stress; while the stiffener type is applicable to the condition of high sealing stress but short sealing time. The boss type has high synthetic performance, which can be applicable to the condition of high sealing stress and long sealing time.