A head mount display support includes a support body including two telescopic arms overlapped with each other, a knob shaft configured to move into an overlapping part of the two telescopic arms when being pressed, an adjustment gear sleeved on the knob shaft to mesh with the two telescopic arms and drive the two telescopic arms to move towards or away from each other, a rear housing arranged on a side of the overlapping part away from the knob shaft, an elastic member with an end fixed to the rear housing and a locking member; another end of the elastic member is connected with the locking member; when the knob shaft retracting, the knob shaft drives the adjustment gear to move away from the overlapping part, the elastic member drives the locking member to bounce into the overlapping part to lock a relative position of the two telescopic arms.