The invention discloses a solar-driven solution membrane concentration and solution dehumidification device and a dehumidification method. The device comprises a solar heat collecting module, a solution membrane concentration module and a solution dehumidification module which are connected. The solar heat collecting module comprises a solar heat collector in circulating connection with a saline solution-water heat exchanger. The solution membrane concentration module comprises a hollow fiber membrane assembly connected with the saline solution-water heat exchanger and a solution storage tank connected with the hollow fiber membrane assembly. The solution storage tank is connected with the saline solution-water heat exchanger and the solution dehumidification module. The solution dehumidification module comprises a padding type solution spray dehumidifier in circulating connection with the solution storage tank. Solar energy is adopted as a drive heat source for heating an absorptive saline solution; the hydrophobic hollow fiber membrane assembly is adopted as a carrier, and the saline solution is condensed and stored based on an air purging type membrane distillation mechanism; and the padding type solution spray dehumidifier is adopted for carrying out dehumidification on dehumidified air, and the functions of adjustment on indoor humidity and energy saving of the whole system are achieved.