The invention relates to an adjustable rail vehicle guiding mechanism. The guiding mechanism is composed of a cast iron platform, a linear guiding rail assembly, a linear gear rail, two guiding tackle assemblies, two lifting table assemblies and two driving device assemblies; the cast iron platform is pre-buried on the ground, and the linear guiding rail assembly and the linear gear rail are mounted on the cast iron platform; the guiding tackle assemblies are mounted on the linear guiding rail assembly; the lifting table assemblies are mounted on the guiding tackle assemblies and can slide up and down relative to the guiding tackle assemblies; one ends of the driving device assemblies are fixed to the guiding tackle assemblies, and the other ends of the driving device assemblies are engaged with the linear gear rail; and the driving device assemblies move along the linear gear rail and synchronously drive the guiding tackle assemblies and the lifting table assemblies to move. The guiding mechanism is simple in structure, safe, reliable, high in universality and suitable for vehicles of various gauges or bogies.