The invention discloses a measuring device and method for a vacuum sealing performance. The device comprises a first standard leaking hole (1), a second standard leaking hole (2), a third standard leaking hole (3), a getter pump (4), a sealed container (5), an angle valve (6), a current-limiting holes (7), a molecular pump group (8), a first dry mechanical pump (9), a gate valve (10), a vacuum gauge (11), a quadrupole mass spectrometer (12), and a measuring chamber (13). In addition, according to the method, an overall leakage rate of the sealed container (5) is measured by using a dynamic method or a static accumulation method and thus a sealing performance of the sealed container is represented; the dynamic method is suitable for large-leakage-rate measurement and the measuring range is associated with a minimum detectable signal and orifice conductance of the quadrupole mass spectrometer (12); and the static accumulation method is suitable for low-helium-leakage-rate measurement and the helium leakage rate of the sealed container (5) is calculated based on measurement on helium partial pressures accumulated in the room by the quadrupole mass spectrometer.