To provide a ratchet pulley for tensioning rope capable of fixing rope at a definite point, having an anti-slip effect, capable of being combined with a car cover or a boat cover to keep the rope tensioned for preventing the cover from falling due to strong wind, capable of being locked and provided with practical functions.

The ratchet pulley for tensioning rope comprises a pulley 1 main body primarily comprising a seat member 10 and a lid member 20. Two rollers 13, a rotary disk 30, a rotary wheel 35, a screw support 40 and a lock member 50 are provided inside the pulley 1. A pawl 41 and a spring fixing section 42 are provided on two sides of the screw support, the spring fixing section is interlocked with a spring 43 to elastically restore its position after the screw support is turned. The pawl is brought into contact with a one-way ratchet 37 of the rotary wheel to connect the screw support and a turning knob 55 outside of the lid member. Turning of the ratchet is controlled by the turning knob to form the function of permitting the rope to move in one direction and the anti-slip/fixing function. Further, the lock member is combined with a lock so that the pulley can be locked and unlocked.