A kind of all-solid-state single-longitudinal-mode Nd∶YVO4 pulse laser based on electro-optical cavity-dumping technology is designed and fabricated. The thermal depolarization originated from the nonuniform pump and laser absorption of the two RTP crystals is reduced via precise temperature control of the pockels cell, and the polarization extinction ratio of the pockels cell is consequently improved. By optimizing the fall time of the pockels cell driver, the problems such as pulse width broadening and power dropping due to the too long time of falling edge are all overcome. At the pump duty cycle of 50%, the incident peak pump power of 16.9 W and the repetition rate of 200 Hz, the single-longitudinal-mode pulse laser with pulse width of 2.85 ns, peak power of 1 MW is obtained. The measured peak power fluctuation of output pulse is less than ±1.8% during a given time of 50 ms, and the time jitter of pulse rising edge is less than ±0.2 ns during 1300 shots.