With the advancement of renewable energy sources such as photovoltaic plants and wind farms, the capacity of the DC grid is increasing rapidly. Larger grid capacity results in higher requirements of current load and interruption capacity in the DC circuit breaker (DCCB). However, the capacity of a single vacuum switch is limited to load several kiloampere system currents. Parallel vacuum switches are needed to achieve higher load capacity. In this paper, to analyze the current transfer in parallel vacuum switches, a DC short-circuit simulation model is established with DCCB consisting of two parallel vacuum switches. The short-circuit current transfer between parallel vacuum switches and interruption characteristics of DCCB with different fault currents and tripping time intervals are investigated. From the experimental results, with the same tripping time interval, higher short-circuit current results in longer current transfer time. With larger tripping time intervals, the longer time current transferring will be used. The paper provides the maximum tripping time interval when the current cannot be completely transferred. It shows that in a DC system with a high load current, parallel vacuum switches can be used in DCCB with short tripping time intervals.