High carbon pearlitic steel is processed by laser shocking processing (LSP). The microstructure and hardness of high carbon pearlitic steel are examined using scanning electron microscope (SEM) and transmission electron microscope (TEM) and microhardness tester. The results show that the cementite lamellae is bent, fractured and spheroidized after multiple LSP impacts. With increase of LSP times, the spheroidization of the cementite lamellae is aggravating at the center of the laser spot, and the dissolution of the cementite is increased, supersaturated carbon atoms are dissolved in ferrite, leading to the increase of the lattice parameters. Moreover, the microhardness increases with increase of LSP times. After multiple LSP impacts, the microhardness at the center of the laser spot increases from 300 HV to 333 HV (2 LSP impacts), 353 HV(6 LSP impacts).