The invention discloses a brace capable of preventing foot drop and relates to the technical field of medical auxiliary instruments. The brace comprises a hard outer protective shell (1), an inner flexible pad, a binding band A (3) for binding the shank, a pair of binding bands B (6) for binding the ankle, a pair of tightening bands (4) and an antiskid bottom (5), wherein the L-shaped hard outer protective shell (1) is provided with a group of air holes (1-1) and comprises a shank protecting section and a foot protecting section. The brace has the advantages that the brace is reasonable in structural design and convenient to wear, the flexion-extension angle of the foot sole can be adjusted through the tightening bands, and the pad is detachable and convenient to clean; a user can walk while wearing the brace with the antiskid bottom, and the brace is good in auxiliary treatment effect on the foot drop caused by various causes such as common peroneal nerve paralysis, spinal cord injury, stroke, hemiplegic paralysis, craniocerebral injury and late poliomyelitis and is good in practical value.