The invention provides recycled polycarbonate reinforced and toughened through an isomeric crosslinking method and a preparation method of the recycled polycarbonate and relates to a plastic material and a preparation method thereof. Firstly, recycled polycarbonate is subjected to forced air drying for 6-8 hours at the temperature of 80 DEG C; the dried recycled polycarbonate, a crosslinking master batch and inorganic filler are weighed according to the weight proportion and put in a high mixer to be mixed for 4-6 min, extrusion palletizing is conducted through a double-screw extruder at the temperature of 220 DEG C to 280 DEG C, and then the product is obtained. According to a traditional recycling method, an elastomer toughening agent is added for toughening, usually the tensile property of polycarbonate recycled materials is reduced, and therefore the whole mechanical performance is affected. According to the technical scheme, the effects of reinforcing and toughening the recycling polycarbonate can be achieved at the same time, the toughness and strength of regenerated polycarbonate can be good without adding compatilizer in the regeneration process of the recycled polycarbonate, and high market promotional value is achieved.