The invention provides an optical detection device which comprises a base, a screw, a fixed image-shooting module and two movable image-shooting modules. The screw is arranged on the base; the fixed image-shooting module is fixed on the base; and the two movable image-shooting modules are respectively arranged at both sides of the fixed image-shooting module and combined with the screw; and the two movable image-shooting modules synchronously approach or move away from the fixed image-shooting module when the screw rotates. The optical detection device not only reduces the part number of the optical detection device to decrease the cost, but also simplifies the position-adjusting operation of the image-shooting modules and further achieves the aim of enhancing the detection stability.