The invention relates to an opening control method for a high-voltage direct-current circuit breaker. The opening control method comprises the steps of switching on a cut-off branch and switching off a through-flow branch when a fault current is detected; determining whether an opening instruction from a control protection system is received or not; if the opening instruction is received, switching off the cut-off branch to complete opening of the direct-current circuit breaker; and if the opening instruction is not received by the direct-current circuit breaker, re-switching-on the through-flow branch and switching off the cut-off branch to prohibit opening of the direct-current circuit breaker. According to the method, the opening operation of the direct-current circuit breaker is performed in two steps; the opening process or the re-opening operation is completed according to whether the opening instruction from the control protection system is received or not; and therefore, the opening precision is ensured while the opening speed of the direct-current circuit breaker is remarkably improved.