Frequency　shift　keying　(FSK)　is　one　of　the　popular　technologies　in　low-voltage　power　line　carrier　(LPLC)　communication　for　its　simple　implementation　and　low　cost.　Nevertheless,　the　currently　existing　implementations　of　it　hardly　meet　the　performance　requirements　of　users　in　a　practical　LPLC　system,　which　hinders　its　widespread　use.　In　order　to　solve　the　problem,　a　novel　FSK　digital　demodulation　method　based　on　adaptive　threshold　algorithm　is　proposed.　As　a　digital　demodulation　method,　it　can　reduce　the　negative　impacts　caused　by　the　hardware　accuracy　in　the　system.　Meanwhile,　the　adaptive　threshold　can　adjust　itself　to　the　change　of　noise　and　attenuation　in　low-voltage　power　line　channel,　which　further　improves　the　system　performance.　Simulation　results　show　that　the　adaptive　threshold　in　our　method　can　adapt　to　the　change　of　channel　condition　under　different　signal-to-noise　ratios　(SNR)　and　attenuation,　which　is　consistent　with　the　theoretical　analysis.　Thus　the　problem　of　how　to　choose　the　synchronous　detection　threshold　could　be　solved　effectively　and　then　the　system　performance　is　improved　accordingly.　©　2012　Binary　Information　Press.