The invention discloses a type selection method for a direct-current breaker used in a multiterminal flexible direct-current transmission system. The type selection method includes the steps that all convertor stations are made to have a double-pole short-circuit fault; the control mode and transmission power of the convertor stations are adjusted, the convertor stations except the convertor station connected with a direct-current breaker set with the type to be selected are set according to the optimal control mode and the optimal transmission power obtained when the largest short-circuit current is generated in the convertor stations, and the first largest current of the side, close to the corresponding convertor station, of the setting position of the direct-current breaker set with the type to be selected and the occurrence time of the first largest current are obtained; the convertor station connected with the direct-current breaker set with the type to be selected is set according to the optimal control mode and the optimal transmission power, and the second largest current of the side, away from the corresponding convertor station, of the setting position of the direct-current breaker set with the type to be selected and the occurrence time of the second largest current are obtained; the type of the direct-current breaker set with the type to be selected is selected according to the larger one of the first largest current and the second largest current and the occurrence time of the larger one. The direct-current breaker selected through the method can be used for various faults and is wide in application range.