The invention belongs to the field of special engineering plastics, in particular to a polyether-ether-ketone/organic montmorillonite composite material and a preparation method thereof. Calculated by the mass, the polyether-ether-ketone/organic montmorillonite composite material is prepared by controlling the temperature in all sections of the charging barrel of a double-screw extruder after changing the addition (1 portion to 20 portions) of the organic montmorillonite with 100 portions of polyether-ether-ketone as reference. The polyether-ether-ketone/organic montmorillonite composite material can have properties, such as higher strength, modulus, the same processing window with polyether-ether-ketone, size stability and the like by adding a small amount of organic montmorillonite (1 portion to 10 portions); in addition, because montmorillonite is natural, the resource is rich and the price is low, a large amount of montmorillonite (15 portions to 20 portions) can be added, so as to reduce the cost of the polyether-ether-ketone composite material and not to affect the use properties.