A method for determining the closing time of a circuit breaker, the circuit breaker outputting a three-phase voltage signal, characterized in that the method comprises: sampling a voltage signal (uA, uB, uC) of a target phase in the three-phase voltage signal of the circuit breaker; determining a first time period according to a voltage value of the sampled voltage signal by determining an absolute value of the voltage value of the sampled voltage signal; determining a second time period during which the absolute value of the voltage value is greater than or equal to a first preset voltage threshold value for n seconds consecutively for the first time, where n is a preset positive number and the first preset voltage threshold value is a positive number; determining any time in the second time period as a jump reference time (A4, A5, B4, B5); and determining the first time period according to the jump reference time by taking the time p voltage cycles before the jump reference time as the start time; taking the time q voltage cycles after the jump reference time as the end time; and determining the time period from the start time to the end time as the first time period, wherein p and q are positive numbers, and the voltage cycle is the cycle of a voltage signal of a target phase input to the circuit breaker; finding, in case a voltage signal in the first time period comprises a voltage jump point (E, F) of a voltage value, the voltage jump point (E, F) of the voltage value in the first time period according to a change in the voltage value of the voltage signal in the first time period; and determining the closing time of a target phase of the circuit breaker according to the found sampling time (A2, B2, C2; A3, B3) of the voltage jump point. sampling a voltage signal (uA, uB, uC) of a target phase in the three-phase voltage signal of the circuit breaker; determining a first time period according to a voltage value of the sampled voltage signal by determining an absolute value of the voltage value of the sampled voltage signal; determining a second time period during which the absolute value of the voltage value is greater than or equal to a first preset voltage threshold value for n seconds consecutively for the first time, where n is a preset positive number and the first preset voltage threshold value is a positive number; determining any time in the second time period as a jump reference time (A4, A5, B4, B5); and determining the first time period according to the jump reference time by taking the time p voltage cycles before the jump reference time as the start time; taking the time q voltage cycles after the jump reference time as the end time; and determining the time period from the start time to the end time as the first time period, wherein p and q are positive numbers, and the voltage cycle is the cycle of a voltage signal of a target phase input to the circuit breaker; determining an absolute value of the voltage value of the sampled voltage signal; determining a second time period during which the absolute value of the voltage value is greater than or equal to a first preset voltage threshold value for n seconds consecutively for the first time, where n is a preset positive number and the first preset voltage threshold value is a positive number; determining any time in the second time period as a jump reference time (A4, A5, B4, B5); and determining the first time period according to the jump reference time by taking the time p voltage cycles before the jump reference time as the start time; taking the time q voltage cycles after the jump reference time as the end time; and determining the time period from the start time to the end time as the first time period, wherein p and q are positive numbers, and the voltage cycle is the cycle of a voltage signal of a target phase input to the circuit breaker; taking the time p voltage cycles before the jump reference time as the start time; taking the time q voltage cycles after the jump reference time as the end time; and determining the time period from the start time to the end time as the first time period, wherein p and q are positive numbers, and the voltage cycle is the cycle of a voltage signal of a target phase input to the circuit breaker; finding, in case a voltage signal in the first time period comprises a voltage jump point (E, F) of a voltage value, the voltage jump point (E, F) of the voltage value in the first time period according to a change in the voltage value of the voltage signal in the first time period; and determining the closing time of a target phase of the circuit breaker according to the found sampling time (A2, B2, C2; A3, B3) of the voltage jump point.