Abstract: A nuclear fusion system comprises: a muon generation unit to generate negative muons including electron and positron accelerators for generating electron and positron beams; a gas supply unit to supply to circulate gaseous deuterium or gaseous deuterium-tritium mixture as raw material gas; a Laval nozzle to accelerate the raw material gas to supersonic velocity; and a shock wave cone connected to the Laval nozzle to introduce the raw material gas accelerated to supersonic velocity to generate an oblique shock wave, the raw material gas accelerated to supersonic velocity being introduced into the shock wave cone to generate the oblique shock wave, the oblique shock wave being decelerated to create a high-density gas target in an in-flight manner, the muons generated as a result of causing electrons and positrons to collide with each other being introduced into the high-density gas target thereby to cause a muon-catalyzed nuclear fusion reaction to occur.