An oil cave depot solution dehumidification system based on cave depot cooling capacity and solar energy comprises a dehumidification packed tower arranged in an oil cave depot. The dehumidification packed tower is provided with a draught fan I. A solution box I is arranged at the lower end of the dehumidification packed tower and is connected with a liquid storage box I, a cooler and a liquid storage box II. The liquid storage box II is connected with a solution box II. An electric heater is arranged in the solution box II. A regeneration packed tower is arranged at the upper end of the solution box II and is connected with a draught fan II. The solution box II is connected to the upper end of the regeneration packed tower and the position of an inlet of the liquid storage box II througha three-way valve II. By means of the oil cave depot solution dehumidification system, the energy consumption is lowered; and independent control and overhaul are convenient, and promotion of application of the solution dehumidification technology in the technical field of building environment control is facilitated.