High　step-up　dc-dc　converter　is　generally　used　in　microgrid,　uninterruptible　power　supply,　hybrid　electric　vehicle,　and　other　applications.　For　attaining　high　boosting　and　high　efficiency,　a　high　step-up　soft-switching　circuit　topology　with　an　integrated　Y-source　network　is　presented.　Its　front　end　is　a　boost　structure　with　the　strengths　of　continuous　and　low　ripple　input　current.　The　active　clamp　circuit　may　store　the　energy　of　leakage　inductance　in　the　output　capacitor　and　then　output　with　reuse.　In　addition,　the　switches　achieve　zero-voltage　conduction,　thereby　decreasing　its　switching　loss.　At　the　same　time,　the　coupling　inductor　achieves　zero　dc　bias,　which　reduces　the　core　size　and　core　loss.　The　converter　may　attain　high　step-up　by　selecting　the　proper　turns　ratio　of　the　coupling　inductor　at　a　reasonable　duty　cycle.　This　article　elucidates　the　working　mode　of　the　converter　in　depth,　builds　the　small-signal　model,　and　studies　the　stability　of　the　converter.　Finally,　an　experimental　prototype　of　200-W,　28-380　V,　and　100　kHz　is　built,　and　the　feasibility　of　the　presented　converter　is　demonstrated　in　both　dynamic　and　static　aspects　of　the　experiment.