The invention relates to a laser welding tractable polycarbonate composition and a preparation method thereof. The composition comprises the following components in parts by weight: 50-80 parts of polycarbonate (PC) resin, 15-40 parts of ABS resin, 5-10 parts of amelt reinforcing agent, 0.1-1 part of a near infrared laser absorbent, 0.1-1 part of an antioxidant and 0.1-1 part of a lubricant. The preparation method of the alloy comprises the following steps: (a) mixing the PC resin, the ABS resin, the melt reinforcing agent, the near infrared laser absorbent, the antioxidant and the lubricant in a mixing agitator; and (b) performing blending granulation on the mixture obtained in the step (a) by virtue of a twin-screw extruder to obtain a product. Compared with the prior art, the polycarbonate composition provided by the invention is higher in melt strength after the melt reinforcing agent is added, so that the surface of a product after welding has no bulges orbreakdowns, welding can be performed under a higher laser intensity, the obtained product is higher in welding strength at the same time, a processing window of a laser welding process of the polycarbonate composition is broadened, and the laser welding tractable polycarbonate composition is obtained.