The invention discloses a converter valve module unit. The converter valve module unit comprises at least one direct-current supporting capacitor, an equalizing resistor, four power semiconductor switch modules, a bypass switch and a secondary control protective unit, wherein the equalizing resistor is connected in parallel with all the direct-current supporting capacitors; the first and second power semiconductor switch modules are sequentially connected in series with each other and then are connected in parallel with the direct-current supporting capacitors; the third and fourth power semiconductor switch modules are sequentially connected in series with each other and then are connected in parallel with the direct-current supporting capacitors; the bypass switch is connected in parallel with the second power semiconductor switch module; the converter valve module unit also comprises a power diode; the anode of the power diode is connected with the negative end of the second power semiconductor switch module; the cathode of the power diode is connected with the negative end of the first power semiconductor switch module. The structure can solve the problems that in existing flexible power transmission, the transmission power is limited by elements, equipment is relatively low in efficiency and the protection reliability is poor when equipment has faults. The invention also discloses a modular multi-electric-level current converter.