The invention discloses a 
hybrid direct-current transmission converter. The 
hybrid direct-current transmission converter is provided with four topological structures which are series connection circuits formed by combining anodes and cathodes of 
current source type valve group units and positive electrodes and negative electrodes of 
voltage source type valve group units in different 
modes. Each 
current source type valve group unit only comprises a 
current source type valve group or comprises a current 
source type valve group and a bypass switch or comprises a current 
source type valve group, a bypass switch and a disconnecting link 
assembly. Each 
voltage source type valve group unit only comprises a 
voltage source type valve group or comprises a 
voltage source type valve group and a bypass circuit or comprises a 
voltage source type valve group, a bypass circuit and a disconnecting link 
assembly. A direct-current transmission device composed of the 
hybrid direct-current transmission converter effectively solves the problem of commutation failures of a direct-current 
transmission system based on thyristors and the problem of direct-current faults of a direct-current 
transmission system based on a 
voltage source converter, and has the advantages that loss is low, a reactive compensation device is not needed or a small number of reactive compensation devices are needed, and the direct-current transmission device can be connected into a passive alternating-current 
system and has the inverse 
power output function.