The invention relates to the field of concentration basin coal slime water measurement in coal washery and discloses a concentration basin step concentration polling-type automatic measurement device.The device is formed by a concentration basin, an A-layer coal slime water feed pipe, a B-layer coal slime water feed pipe, a C-layer coal slime water feed pipe, a D-layer coal slime water feed pipe,an E-layer coal slime water feed pipe, an A solenoid valve, a B solenoid valve, a C solenoid valve, a D solenoid valve, an E solenoid valve, a feed gathering pipe, a pump, a discharge vertical pipe,a discharge return pipe, a densimeter and an electric control device. A feed port of the pump is connected with the feed gathering pipe; the feed gathering pipe is connected with the A, B, C, D and Ecoal slime water feed pipes; and each feed pipe is equipped with one solenoid valve. Through cycle control of on / off states of the solenoid valves, density of coal slime water at different depths is measured indirectly, and the density is converted into a corresponding concentration value through corresponding calculation, thereby realizing measurement of concentration of the coal slime water at different depths. The automatic measurement device is stable and reliable, simple in structure, and high in degree of automation.