By using femtosecond laser pulses with two different wavelengths separately interacted with the silicon sample, it′s experimentally demonstrated that under the same laser fluence, the fabricated surface microstructure of silicon is determined by the relation between laser power and pulse number. During the fabrication process, pulse number represents the interaction time between laser pulses and sample, which determines the depth of energy transferred into the inner part of material; while the laser power represents the ability of laser to ablate and volatilize the material. The optimal selection of the laser power and pulse number can produce the microstructured silicon with a high spike height, which can realize the effective absorption of micro/nano silicon-based PV material in a wide wave band. These results are important for the efficient fabrication, surface morphology control, and the corresponding photoelectrical properties of surface-microstructured materials.