The invention provides a cooling device, a control method, a
compression system and an air conditioner, the cooling device comprises a cooling unit and a
vacuum pump, the cooling unit comprises an
oil storage tank and an oil conveying tank, an oil inlet and an exhaust port are formed in the upper end of the oil conveying tank, and an oil outlet is formed in the lower end of the oil conveying tank; the oil inlet pipeline communicates with the
oil storage tank and the oil inlet. The exhaust pipeline communicates with the
vacuum pump and the exhaust port. Under the action of the
vacuum pump, air in the oil conveying tank is exhausted, so that negative pressure is formed in the oil conveying tank; under the action of negative pressure, cooling oil in the
oil storage tank enters the oil conveying tank through the oil inlet pipeline, and then the cooling oil in the oil conveying tank is output through the oil outlet pipeline; the scheme that the vacuum pump replaces a traditional
oil pump is adopted, cooling oil in the oil
storage tank is input into the oil conveying tank through negative pressure, then the cooling oil is output through gravity, and conveying of one or more kinds of cooling oil is achieved; due to the characteristic of negative pressure driving, the device is not influenced by the
viscosity of cooling oil and can be compatible with cooling oil with different rheological characteristics; when cooling oil is replaced, only the oil conveying tank and the corresponding pipeline need to be cleaned.