The　high　voltage　circuit　breaker　is　a　kind　of　the　key　equipment　in　power　system,　and　spring　operating　mechanism　is　one　of　the　most　widely　used　operating　mechanisms　of　the　high　voltage　circuit　breaker.　Because　of　the　high　speed　of　the　moving　contact,　hydraulic　buffers　are　often　used　to　absorb　the　remaining　kinetic　energy　of　the　moving　parts.　In　this　paper,　based　on　the　theory　of　multi-body　system　dynamics　and　hydraulic　cushioning,　the　dynamic　simulation　model　of　spring　operating　mechanism　of　the　high　voltage　circuit　breaker　with　the　hydraulic　buffer　is　established　by　using　ADAMS　and　AMESim　software.　The　dynamic　characteristics　of　the　high　voltage　circuit　breaker　operating　mechanism　in　the　closing　and　opening　stage　are　simulated,　and　dynamic　parameters　and　fluid　parameters　are　obtained,　such　as　the　closing　and　opening　speed　of　the　operating　mechanism　and　the　pressure　of　the　hydraulic　buffer.　The　coupling　simulation　model　could　provide　theoretical　guidance　for　the　structural　design　and　optimization　of　spring　operating　mechanism　of　high　voltage　circuit　breakers.　©　2020　Institution　of　Engineering　and　Technology.　All　rights　reserved.