The invention discloses a high-energy monomode plasma ignition system capable of detecting ionization, comprising a boosting transformer composed of a primary winding and a secondary winding; a single energy source connected with the primary winding, wherein the single energy source is a capacitor; a spark plug gap connected with the secondary winding, wherein the energy generated by the capacitor generates sparks in the spark plug gap after passing through the primary winding and the secondary winding; an additional circuit, wherein one end of the circuit is connected with the primary discharging end of the capacitor and the other end of the circuit is connected with the spark plug gap. The capacitance energy source can be used to generate primary high-voltage sparks and puncture the spark plug gap, and also provide subsequent currents to continue burning of the high-energy plasma arc. In comparison with the current ignition systems, the plasma ignition system combined with the ionization detection can produce needed high-energy sparks by just one capacitor to ignite gas-oil mixtures, and maintain the high voltage which generates the ionization current, and is convenient to be installed together with a coil ignition system on a spark plug. The plasma ignition system has advantages of small volume, high cost efficiency and so on.