In order to obtain a dual frequency pulsed laser with high peak power, good coherence and large frequency difference, a diode-pumped passively Q-switched two-cavity dual-frequency Nd∶YAG laser is designed, which adopts a structure composed of two T-shaped standing-wave cavities sharing a common gain medium. An intracavity polarizing beam-splitter and a half wave-plate are combined to form a birefringent filter acting as the laser longitudinal mode selector, a piece of Cr 4+∶YAG crystal is chosen as a passive Q-switch, and thus the p-component and s-component of this 1064 nm laser are forced to oscillate simultaneously in a single longitudinal mode within the linear and right angle cavities, respectively. The output of orthogonally and linearly polarized dual-frequency pulsed laser at 1064 nm is realized. In addition, the rate equation group of a passively Q-switched two-cavity Nd∶YAG laser is established and the output characteristics of two-cavity pulsed laser are analyzed theoretically. Moreover, both the oscillation and output characteristics of this two-cavity dual-frequency pulsed laser are investigated experimentally. The experimental results show that, when the pump power of laser diode is 2.7 W, as for the p-polarization single-frequency pulsed laser output from the linear cavity, the repetition frequency, pulse width and peak power are 5.8 kHz, 42 ns and 126.4 W, respectively. In contrast, as for the s-polarization single-frequency pulsed laser output from the right angle cavity, those are 5.8 kHz, 40 ns and 133.6 W, respectively. The frequency-difference of this dual-frequency pulsed laser is approximately 10 GHz. This dual-frequency pulsed solid-state laser has a wide application prospect in the fields of laser interferometry, lidar coherent detection, and so on.