The discovery of ultrafast demagnetization has introduced a new approach for generating ultrafast spin currents using an ultrashort laser, potentially enabling faster manipulation of material magnetism. This has sparked research into the transport mechanisms of ultrafast spin currents. However, the underlying processes remain poorly understood, particularly the factors influencing interlayer spin transfer. This study employs a superdiffusive spin transport model to investigate the ultrafast spin transport mechanisms in the Ni/Ru/Fe spin valve system, with a particular focus on how interlayer spin transfer affects the ultrafast magnetization dynamics of the ferromagnetic layer. First, by calculating the laser-induced magnetization dynamics of the Ni/Ru/Fe system under different magnetization alignments, the study validates recent experimental findings. Further analysis reveals that reducing the thickness of the Ru spacer layer significantly enhances the spin current intensity and increases the demagnetization difference in the Fe layer, confirming the key role of the hot electron spin current generated by the Ni layer in interlayer spin transport. Additionally, the spin decay length of hot electron spin currents in the spacer Ru layer is determined to be approximately 0.5 nm. This study also shows that laser-induced transient magnetization enhancement can be achieved by adjusting the relative laser absorption in the films. These results provide theoretical support for the future ultrafast magnetic control of spin valve structures and contribute to the advancement of spintronics in high-speed information processing and storage applications.