A high-voltage pulse discharge capacitor of an elongated structure comprises a capacitor body. The capacitor body comprises several high-voltage capacitor parallel units and a high-voltage capacitor core pack. The several high-voltage capacitor parallel units are mutually connected in parallel. The high-voltage capacitor parallel units connected in parallel are then connected as a whole with the high-voltage capacitor core pack in parallel. The high-voltage capacitor parallel unit comprises two capacitor core packs. The two capacitor core packs are mutually connected in parallel. The capacitor core packs connected in parallel are wrapped with a PP film and purple copper foil at an outer side integrally. The purple copper foil is connected to axial faces located at a head and a tail of a combination integral of the two capacitor core packs. Using a preceding parallel connection mode enables the capacitor to provide greater current when discharging electricity, reduces heat generated by internal resistance when the capacitor discharges the electricity, and prolongs a service life of the capacitor.