With uniformly side-around arranged compact pumping structure, high conversion efficiency operating of diode-laser-array side-pumped Nd∶YAG ceramic laser was demonstrated. Using a 5 mm×75 mm sized Nd∶YAG ceramic rod with 1% dopant fraction of number of atoms, the laser generated a quasi-continuous-wave (QCW) output with an average power of about 230 W at 1064 nm, and the output coupler transmission was 22%, which corresponded to the calculated result of 22.2%. The optical-to-optical conversion efficiency was 52.4%, and the slope efficiency was 61%. Besides, the pulse width of the beam was detected to be 160 μs, the line width was less than 0.8 nm， and the beam divergence angle was 16 mrad. The experiment results showed that the output power Nd∶YAG ceramic laser was comparable to that of Nd∶YAG single crystal laser.