Gas coupling type hydrodynamic cavitation device

The invention discloses a gas coupling type hydrodynamic cavitation device, and relates to the technical field of sludge dewatering, the gas coupling type hydrodynamic cavitation device specifically comprises an outer cylinder, an inner cylinder and a cavitation mechanism arranged in the outer cylinder, the cavitation mechanism comprises a perforated plate and a nozzle, and the nozzle is internally provided with at least one contraction section with a reduced sectional area. The hydrodynamic cavitation structure design is introduced, so that the sludge dewatering performance is improved by 10%-20% or even higher compared with that of a conventional process, the cost is reduced by 30%-50%, the performance is improved by 5%-10% compared with that of a similar process, and organic matters difficult to biochemically degrade in effluent are preliminarily oxidized and degraded; and then, through cavitation design of a partition plate and the like, organic pollutants in the effluent are further effectively degraded,