The invention discloses a solar and GSHP (ground source heat pump) combined energy supply system for buildings. The sytsem provided by the invention comprises two subsystems, namely a solar and auxiliary GSHP system and a pure GSHP system, wherein the solar and auxiliary GSHP system comprises a solar thermal collector, a thermal storage water tank, a GSHP unit No.1, a ground heat exchanger No.1, a collected heat circulating water pump, a unit ground source collateral circulation water pump No.1, a unit user collateral circulation water pump No.1, indoor end equipment, a collected heat controlvalve, a heat accumulation control valve, solar supply heat control valves No.1 and No.2, a unit ground source collateral control valve No.1, a unit user collateral control valve No.1, heat accumulation/heat supply operational mode switch control valves No.1-No.4 and a connecting line; the pure GSHP system comprises a GSHP unit No.2, a ground heat exchanger No.2, a unit ground source collateral circulation water pump No.2, a unit user collateral circulation water pump No.2, indoor end equipment, a unit ground source collateral control valve No.2, a unit user collateral control valve No.2 and a connecting line.