We　report　on　a　high-pulse-energy　solid-state　picosecond　Nd:YVO4　oscillator　with　cavity-dumping.　The　laser　is　end-pumped　by　an　808　nm　laser　diode　and　passively　mode-locked　with　a　semiconductor　saturable　absorption　mirror　(SESAM).　In　pure　cw-mode-locking,　this　laser　produced　2.5　W　of　average　power　at　a　pulse　repetition　rate　of　40　MHz　and　pulse　duration　around　12　ps.　A　cavity　dumping　technique　using　an　intra-cavity　BBO　electro-optic　crystal　to　which　bidirectional　voltage　was　applied　was　adopted,　effectively　improving　the　cavity-dumping　rate.　Tunable　high　repetition　rate　from　100　kHz　to　1　MHz　was　achieved.　With　electro-optic　cavity　dumper　working　at　1　MHz　repetition　rate,　we　achieved　average　power　594　mW.　The　laser　includes　a　5　mm　long,　a-cut,　0.5%　doped　Nd:YVO4　crystal　with　a　5-degree　angle　at　one　end　face.　Laser　radiation　is　coupled　out　from　the　crystal　end　face　with　a　5-degree　angle,　without　requiring　insertion　of　a　thin-film　polarizer　(TFP),　thus　simplifying　the　laser　structure.　This　picosecond　laser　system　has　the　advantages　of　compact　structure　and　high　stability,　providing　a　good　oscillator　for　regenerative　amplifiers.