High repetition rate, large energy and narrow pulse width laser is widely used in the frontier fields of laser imaging, laser machining and precision measurement. Using the technology of electro-optical cavity-dumped and double rod series structure, which reduces the thermal lens effect and ensures the good matching mode of oscillation light and the pump light, the 1064 nm linearly polarized laser output with high efficiency, large energy and narrow pulse width is realized. Using the barium boron oxide (BBO) Pockels cell as electro-optical switch, and the 914 nm fiber-coupled semiconductor laser with low absorption coefficient is used to pump the Nd∶YVO4 crystal. Thus the thermal stability of the laser is improved. At the repetition rate of 7 kHz and the crystal absorption power of 79.6 W, a stable pulse laser output with a pulse width of 5 ns, maximum average output power of 35 W, and a single pulse energy of 5 mJ is obtained, and the corresponding optical conversion efficiency is 44%.