Abstract: As an active exploration and attempt of renewable energy acCSEE, triple active bridge (TAB) has been widely concerned in the fields of distributed photovoltaic acCSEE, automobiles, and multi-voltage level DC power demand. Due to the increase in the number of switches, the combinations of phase shift angle and duty ratio of TAB have multiplied compared with that of dual active bridge (DAB). The existing piecewise linear calculation method of DAB is not applicable to TAB. The high-frequency-link AC current calculation is the key step of current stress and RMS current, providing the basis for subsequent optimization. This paper proposed a simple solution for TAB high-frequency-link AC current calculation, which can get the current vertices for all the duty ratio and phase-shift angle combinations at the same time. Based on the unified current solution derived, this paper presented a method for calculating the peak and RMS current of TAB. Finally, an experimental platform was built to verify the effectiveness of the proposed method.