The invention discloses a supercritical multisource multielement thermal 
fluid injection-production 
system and injection-production method. The 
system comprises a supercritical multisource multielement thermal fluid generating 
system and an oil tube. The oil tube is arranged in an exploiting shaft; the supercritical multisource multielement thermal fluid generating system comprises a supercritical gasification reactor and a supercritical mixed 
combustion reactor; in the presence of supercritical water, a gasification reaction is performed on fuel 
slurry in the supercritical gasification reactor, and the gasification product of the reaction and 
oxygen-containing gas dissolved in the supercritical water combust in the supercritical mixed 
combustion reactor to form a supercritical multisource multielement thermal fluid containing supercritical water and 
carbon dioxide; the supercritical mixed 
combustion reactor is connected to the oil tube. The supercritical multisource multielement thermal 
fluid injection-production system provided by the invention has the effects that 
thermal efficiency is high, the 
viscosity of thickened oil is reduced, the flowability of the thickened oil is improved and the 
recovery efficiency is increased.