Buck-type　power　factor　correction(PFC)　converters　have　low　voltage　stress　and　strong　input　and　output　current　control　ability,　but　the　input　current　has　naturally　dead　zones　in　traditional　single-phase　Buck-type　PFC　converter,　which　leads　to　high　current　distortion.　A　novel　Buck　PFC　converter　was　proposed,　by　adding　an　auxiliary　switch　and　a　diode.　The　dead　zones　were　eliminated　when　the　converter　operated　in　Buck-Boost　mode　during　the　dead　time.　Based　on　one　cycle　control,　a　nonlinear　control　was　deduced　to　solve　the　transfer　problem　between　Buck　and　Buck-Boost　operating　modes.　The　two　operating　modes　have　the　same　control　strategy,　which　smoothes　the　modes　transfer　and　nearly　unit　power　factor　can　be　achieved.　The　circuit　operating　modes　and　control　strategy　were　analyzed　in　detail,　verified　by　experimental　results　on　a　50　kHz,　100　V/1　A　prototype.　The　total　harmonic　distortion　(THD)　of　input　current　keeps　low　in　the　input　voltage　range　of　175~265　V.　Both　the　two　switches　are　grounded,　simplifying　the　driving　circuits,　and　the　two　operating　modes　have　the　same　control　strategy,　which　make　the　proposed　converter　suitable　for　practical　application.　©　2017,　Harbin　University　of　Science　and　Technology　Publication.　All　right　reserved.