A gas-solid separating method and a gas-solid separating system for simple substance sulphur in sulphur-containing exhaust are provided. The gas-solid separating method for simple substance sulphur in sulphur-containing exhaust comprises the following steps: first, cooling sulphur-containing exhaust at an extremely high speed; then, separating dust; finally, recycling a heavy liquid phase solvent and simple substance sulphur. The system comprises a quick cooling system, a low-temperature washing and purifying system, a light liquid phase and heavy liquid phase separating system, a washing liquid recycling system and a simple substance sulphur recycling system.