A new two-DOF inertial rotary motor using a two-dimensional piezoelectric actuator (PEA) constructed on four bimorphs was developed in this work. The theoretical analyses and finite element method (FEM) simulation were accomplished to design the two-dimensional PEA. The stick-slip mechanism was utilized to implement the rotary motions of the motor. Then the mechanical output performances of the motor were tested and compared with previous work. The experimental results indicated that the maximum rotary velocities of the motor were 263.26 mrad/s around X axis and 268.48 mrad/s around Y axis under voltage of 210 V_p-p and frequency of 630 Hz, respectively. The angular displacement resolutions of 6.27 μrad around X axis and 6.34 μrad around Y axis were achieved under voltage increment of 2.5 V, respectively. This new motor held the advantages of smaller size and larger output speed. This motor could be applied to precision attitude adjustment systems by virtue of its compact size, high resolution and large rotary motion space.