The invention provides a slops collection and cleaning device for subsea pipeline. The Slops collection and cleaning device comprises a slop tank, a slop inlet provided on a slop tank and a slop outlet. The slops collection and cleaning device is characterized in that a slop tank is composed of three slop tanks arranged in sequence, wherein the slop inlet is arranged at the upper part of the first slop tank, the sand cleaning support bucket is arranged in the tank below the slop inlet; the second slop tank is provided with a longitudinal baffle plate, wherein the baffle plate and tank bulkhead compose the angle of 30-80 degree; the upper and lower parts of the third slop tank are respectively provided with a light slop blow-off pipe and a outlet below of slop; in the tank bulkhead of joint part of the first slop tank and the second slop tank, and in the tank bulkhead of joint part of the second slop tank and the third slop tank, the upper and lower parts of both two tank bulkheads of joint part are respectively provided with a common diversion trench and a sand cleaning opening; three upper and power parts of the non-public bulkheads of the slop tanks are respectively provided with a sand cleaning shutter. The slops collection and cleaning device for subsea pipeline has the advantages of being simple principle, simple structure and convenient operation, thereby prolonging the collection and cleaning capacity of subsea pipeline and adapting the environmental protection requests for slop treatment.