The laser processing parameters of the sample guideway are optimized through orthogonal experiment. The microstructure analysis and hardness test of the laser-treated sample are carried out by optical microscopy, scanning electron microscope (SEM) and microhardness tester, and a contrast test of wear-resistance between the laser-treated and normally treated samples is conducted in oil-lubricated conditions. The results show that hardening depth is influenced most strongly by current, followed successively by scanning speed, pulse width and frequency. The optimized laser processing parameters are as follows: 0.25 mm/s for scanning speed, 150 A for current, 10 ms for pulse width, and 7 Hz for frequency. The spheroidal graphite is observed in the melted region of the laser-treated sample. The grain size in the phase transformation region is much smaller than that in the melted region and the grain is more evenly distributed. Compared with the normal treatment, laser processing produces a dramatic improvement in hardness without variation of gradient in distribution. When the cycle number reaches 38000, the wear-resistance of the laser-treated sample is almost one time higher than that of the normally treated one.