The utility model discloses a ratchet wrench, comprising a handle and a working head which is fixedly connected on one end of the handle, and is characterized in that a one-way bearing is arranged in a center hole of the working head, the one-way bearing and the working head are allocated by the splined connection, and the upper end of the one-way bearing is provided with an end cap which is fastened on the working head through a fixed screw. By adopting the one-way bearing, the utility model extends the torque, eliminates the freedom gap, achieves the quick working state of large torque and zero freedom gap, and further provides enough torque. The utility model can be randomly used in the work and the narrow environment, and is compact in structure and small in bulk.