A circulating device comprises a first tee joint (1), a first three-way valve (2), a second tee joint (3), a second three-way valve (4), a buffer
bottle (5), a liquid supplementing pump (6), a third three-way valve (7) and a controller (8), the first tee joint (1) is connected with the first three-way valve (2), the third three-way valve (7) and a
solvent bottle (13), and the first three-way valve (2) is connected with the first tee joint (1), a
liquid phase pump (9) and the second tee joint (3). The second three-way valve (3) is connected with the first three-way valve (2), the surge flask (5) and the second three-way valve (4), the second three-way valve (4) is connected with the
detector (12), the second three-way valve (3) and the collecting end (17), the surge flask (5) is connected with the second three-way valve (3) and the liquid supplementing pump (6), a
solvent overflow port (16) is formed in the upper portion of the surge flask (5), and the liquid supplementing pump (6) is located between the surge flask (5) and the third three-way valve (7). The third three-way valve (7) is connected with the first three-way valve (1), the liquid supplementing pump (6) and the waste liquid port (15). The circulating device has the advantages that
diffusion is avoided, pressure fluctuation is absorbed, normal internal circulation of the
liquid phase pump is ensured, internal collection can be achieved in a circulating mode, and cleaning is easy.