The invention discloses a capacitive graded compact impulse voltage generator comprising a sealing shell, an arc-shaped cover plate, a basin-type insulator and a lead-out wire, and a charging transformer, a charging capacitor, a first high-voltage silicon stack, a second high-voltage silicon stack, a first front-end pulse capacitor, a second front-end pulse capacitor, a first front-end multipolar ignition ball gap, a second front-end multipolar ignition ball gap, a first rear-end pulse capacitor, a second rear-end pulse capacitor, a first rear-end multipolar ignition ball gap, a second rear-end multipolar ignition ball gap, a first wave head resistor, a second wave head resistor, a third wave head resistor, a fourth wave head resistor, a first wave tail resistor, a second wave tail resistor, a third wave tail resistor, a fourth wave tail resistor, a first charging resistor, a second charging resistor, a third charging resistor and a fourth charging resistor which are arranged in the sealing shell. The internal space of the sealing shell is effectively utilized so that the dimension requirement for the sealing shell is further reduced.