In order to reduce the dead-time effect of tri-level shunt active power filter (APF), through the analysis of the production principle and influence factors of dead-time effect in APF, and combining with current flow to the mutations in the actual operation problems, a kind of PWM signal correction scheme based on the current interval judgment is designed. The scheme avoids detecting the current direction directly by setting the current buffers around zero current, by which the interference from current jitter around zero-crossing can be averted in the case of other factors unchanged. In this way the bad influence caused by the dead-time effect on the performance of APF harmonic compensation can be reduced. Last, the proposed schemes are verified by the Matlab simulation, and the results show that not only the vast majority of dead-time is eliminated, but also the redundant switches are removed, thus the harmonic compensation effect is superior to that of the conventional control.