The invention relates to the field of viscometers and discloses a diluted Ubbelohde viscometer. The viscometer comprises a liquid suction/discharge pipe (3) and a measuring tube (2). One side of the measuring tube (2) is connected to an escape pipe (1). The lower end of the measuring tube (2) is connected to a liquid feeding/discharge pipe (7). A mixing ball (6) is connected to the lower part of the liquid suction/discharge pipe (3). The liquid feeding/discharge pipe (7) is inserted into the bottom of the mixing ball (6). The lower end of the mixing ball (6) is connected to a raw liquid inletpipe (61). The opening of the liquid suction/discharge pipe (3) is connected to a liquid suction device (30) and a liquid pushing device (31). The measuring tube (2), the escape pipe (1), the liquid suction/discharge pipe (3) and the raw liquid inlet pipe (61) are connected to switches for controlling pipe opening sealing. The diluted Ubbelohde viscometer realizes convenient sample feeding, has uniform stirring effects, produces accurate measurement results, is cleaned through simple processes and has a high recovery rate of the sample solution and the cleaning solution.