The utility model discloses a railway construction mechanically mixing power supply switched systems, include: hybrid source, and the converter that links to each other with the hybrid source, contactnet power module and internal combustion power module are drawn together to the hybrid source packet, and the electric energy that comes from contact net power module or internal combustion power module converts the electric energy of traction motor needs into after converter transform and processing. Is connected when the electricity with the contact net and switches on and contact net when continuously supplying power, supply power for traction motor through contact net power module. It can not continuously supply power the time, supplies power for traction motor through internal combustionpower module to be connected disconnection or contact net when the electricity with the contact net. When needs when switching between two kinds of power module, contact net power module and internalcombustion power module are switching the in -process simultaneously for the traction motor power supply, the power module who is replaced withdraws from the power supply after the switching. The utility model discloses in the time of can solving two kinds of power supplies switchings, guarantee that operation mechanism can just not have the technical problem who assaults by continuity of operation.