The invention discloses an adjustable ophthalmic operation head fixator. The fixator comprises an outer ring, an inner ring is arranged in the outer ring, a first clamping block is arranged at one endof the inner ring, a second clamping block is arranged at the other end of the inner ring, a nut is arranged on one side of the second clamping block, and an adjusting screw rod is arranged in the nut. According to the fixator, a head position can be fixed, and the deflection of the head position of a patient is avoided; local anesthesia is a common operation mode for the ophthalmology department, has the advantages of being convenient, rapid, low in risk and the like, and meanwhile has the defects that the head position of the patient is prone to shift and suddenly move and the like; due tothe fact that an ophthalmic operation is performed under a microscope, the head position deviation or movement can cause the view movement and a not coaxial microscope light source during operation, and then difficulties are caused to the operation, and even serious complications are caused; and the fixator can fix the head position, prevent the deflection of the head position of the patient during operation, prevent the situation that an operator repeatedly adjusts the head position during operation to prolong the operation time, and reduce the complications during operation.