Effective　reduction　of　the　vibration　in　rotor　and　stator　at　critical　speed　is　important　for　steady　operation　of　rotor　systems.　A　new　transient　field　balancing　method　is　proposed　in　this　paper.　The　empirical　mode　decomposition　(EMD)　method　coupled　with　holospectral　technique　is　used　to　extract　rotating　frequency　information　including　precise　frequency,　amplitude　and　phase　nearby　the　critical　speed　from　the　run-up　vibration　signals.　Reasonable　trial　weights　are　selected　through　estimating　the　unbalance　masses　and　position.　Moreover,　the　correction　masses　and　position　are　obtained　by　holo-balancing　method.　Compared　with　the　traditional　dynamic　balancing　method,　this　method　does　not　need　obtain　steady-state　vibration　signals,　and　the　rotor　can　pass　through　the　critical　speed　smoothly.　The　principle　and　detailed　procedures　of　this　method　are　described　in　this　paper,　and　the　effectiveness　of　the　new　method　was　validated　by　field　balancing　of　rotor　kit　system.