The invention relates to a pipeline tensioning device for a pipe laying ship, which pertains to the field of pipe tensioning devices. The pipeline tensioning device is characterized in that a seat assembly consists of a seat, a micro-motion lifting pedestal and an adjusting screw rod; a frame assembly consists of a frame seat, a lower frame, an upper frame and a lifting frame; the lower frame is arranged on the frame seat; the upper frame is arranged on the lower frame by a flange; the lifting frame can be moved up and down in the upper frame; a driving assembly consists of driving motors, a speed reducer, a driving shaft, a driven shaft and a chain wheel; a lower driving motor is arranged on the lower frame, while an upper driving motor is arranged on the lifting frame; a lifting assemblyconsists of a lifting motor, a speed reducer, a worm wheel and a worm and is arranged on the lifting frame; a track assembly consists of a chain, a carrier roller, a chain wheel and a V-shaped clamping component, and the lower part and the upper part of the track assembly are clamped tightly by air pockets. The pipeline tensioning device is operated and monitored by a control system in a remote manner and has the main advantages of motors for driving and lifting, the air pockets for clamping, fast and stable starting, simple, reliable and electricity-saving control and low cost of pipe layingconstruction.