The utility model discloses a multifunctional valve. The locking ball valve, the filter, the temperature measuring ball valve and the blow-down valve are compactly integrated; the valve obtained through integration can be used as a common ball valve, a locking valve, a filter and a blow-down valve, four purposes of the valve are achieved, the occupied space is reduced, potential leakage points andpotential safety hazards are reduced, and the cleaning mode is simplified.