The utility model provides a submarine pipeline backfills plough, includes: a hydraulic unit, buoyancy unit, put in the unit, keep off native unit, turn to the unit, rear portion support element, anterior support element, wherein, keep off native unit and be equipped with: for supporting the frame, install on the frame the several keeps off native board, should keep off native board through keeping off the both sides of native board link symmetrical arrangement at the frame, it is equipped with to turn to the unit: the triangle adjusting mount, in proper order with the turning to the tie -beam, turn to the swing arm of triangle adjusting rack connection, piston shoes support, still being connected with on the frame and turning to the pneumatic cylinder, it turns to the hydraulic piston pole and turns to the swing arm articulated elements with the second in proper order, turns to the hydraulic piston bar pivot and connect, it turns to the pin joint of swing arm articulated elements with first, second respectively to turn to the hydraulic piston pole, firstly turn to swing arm articulated elements and the pin joint of posture adjustment connecting rod. Hydraulic cylinder piston rod's relative motion regulation four -bar linkage's motion position is hoisted through the direction. The utility model discloses depth of water environmental limit is not received, the backfill to the submarine pipeline ditching can be realized promptly.