<p>The wear of tunnel boring machine cutterheads represents a significant economic burden in tunneling operations. To improve the wear resistance of cutterheads, 300M steel cladding layers were deposited on Q345 steel substrates via laser cladding. A systematic investigation was conducted to evaluate the effects of laser processing parameters on the macrostructure, microstructure, hardness distribution, phase composition, and wear resistance of the coatings, utilizing optical microscopy, scanning electron microscopy, microhardness testing, and tribological experiments. The results indicate that although variations in laser parameters did not alter the phase composition—all coatings consisted primarily of α-Fe—higher scanning speeds markedly intensified the α-Fe diffraction peaks. Compared to laser power, scanning speed exerted a more substantial influence on the overall coating performance: At high scanning speeds, the coatings exhibited the lowest porosity (0.84%) and the highest microhardness (697.1 HV_0.5), which can be attributed to grain refinement and solid solution strengthening effects. Furthermore, the tribological behavior of the 300M steel coating was found to be governed by the stability of the friction layer. The high hardness and densification achieved under high scanning speed conditions suppressed the formation of a FeO friction layer, leading to a transition in the wear mechanism from severe oxidative/adhesive wear (<i>A</i>–<i>C</i>) to mild abrasive wear (<i>D</i>). Consequently, the wear resistance was significantly enhanced, with the wear rate reduced from 81 × 10⁻⁵ to 40.2 × 10⁻⁵ mm³/N·m.</p>