In this paper, in order to eliminate the effect of STATCOM dead-time effect on the voltage and current, a new dead-time compensation method was proposed. According to the principle of discrete-time disturbance observer, corresponding observer was designed. The D-value of STATCOM output voltage and reference voltage caused by dead-time effect can be real-time observed on line. The D-value as a compensation value feeds back to the dead-beat control system to realize the self-adaption dead-time compensation. Simulation and experimental results show that it can effectively improve the effect of dead-time compensation, eliminate the phenomenon of the zero current clamping, and reduce current harmonic content of STATCOM.