In order to ensure safely and smoothly coming down to safe load for 1 000 MW supercritical units when auxiliary equipment tripping occurs, it is important to carry out RUN BACK (RB) tests during debugging process. Taking 2×1 000 MW supercritical units in a power plant as examples, the RB control strategy is studied and optimized in this paper, such as coordination control, fuel control, air volume control and feed water control, according to the units characteristics and previous experience. The RB testing results show that the equipments act correctly, the parameters are controlled within a reasonable range, the function of RB control strategy is perfect, as well as the automatic control effect is good.