A spectral splitting photovoltaic-methane-steam-reforming hybrid system for heat and power cogeneration has been proposed. In the system, sunlight with wavelengths shorter than 870 nm is assigned to photovoltaic cells for direct power and heat cogeneration, while the rest of the solar spectrum is utilized by a methane-steam-reforming reactor via the route of solar thermal energy - chemical energy - heat and power. Analysis reveals that the hybrid system is characterized by high net solar-to-exergy efficiency (40%), high energy storage capability and low-emission energy supply (63% fossil energy saving and 77% carbon-dioxide emission reduction). Primary reasons underlying the excellent performance are full-spectrum optimized utilization of solar energy and comprehensive utilization among solar energy, thermal energy and chemical energy.