The invention relates to a detonation-wave-front high-voltage electric plasma gas relay coupling ignition detonation engine which is formed by a pre-detonation burning pipe (7), a high-voltage ignition head c (8), a high-voltage ignition head, a plasma flow guide pipe (10), an annular face magnetic pole plate (14), a field coil (15), a detonation spraying pipe (16), a current controller (17), a high-voltage ignition-oil injection control ECU (19), a fuel and air premixing chamber (22), an air velocity transducer (25) and a high pressure oil spraying pump (26). Through multi-stage high-voltage ignition and plasma gas discharge, after a tiny pulse detonation wave is subject to three-stage relay coupling ignition, energy is amplified continuously, the best energy is achieved finally, the energy is sprayed out from a fuel gas spraying opening (24), and generation of detonation is guaranteed. The detonation-wave-front high-voltage electric plasma gas relay coupling ignition detonation engine has the beneficial effects that (1) the detonation, control and quick holding of the knock can be solved, and the pulse detonation wave can be gradually amplified; (2) atomization, jetting and doping of liquid fuel and an oxidizing agent can be achieved; (3) stable pushing force can be generated, low frequency to high-frequency continuous work can be achieved; and (4) pulse knock engine power adjustment can be achieved.