An independent power generating device using water pressure and vapor, comprising: a water tank disposed at a predetermined height to have potential energy; a first water wheel disposed at an exhaust side of the water tank to vertically face the water tank and to rotate by head drop of water, an electric generator being coupled to a rotating shaft of the first water wheel; a heating boiler disposed to communicate with a lower portion of the first water wheel to generate vapor by heating inlet water; a vapor wheel disposed to rotate by high-pressure vapor ejected by communicating with a vapor exhausting end of the heating boiler, an electric generator being coupled to a rotating shaft of the vapor wheel; a condensing tank mounted at an upper side of the vapor wheel to have a first side communicating with the vapor wheel so as to condense vapor and to allow condensate water to flow toward an another side to exhaust it; and a second water wheel disposed to downwardly communicate with an exhaust side of the condensing tank, to rotate by head drop of the condensate, an electric generator being coupled to a rotating shaft of the second water wheel, and to downwardly communicate with the water tank; wherein a check valve is formed in the connection pipe to facilitate introduction of the vapor that comes up after the vapor wheel is rotated, into the condensing tank and to prevent the vapor introduced into the condensing tank from flowing backward, and wherein a portion of a second side of the condensing tank communicates with an upper portion of the second water wheel with the connection pipe and a control valve is coupled to the connection pipe to downwardly supply water at a predetermined supply rate. a water tank disposed at a predetermined height to have potential energy; a first water wheel disposed at an exhaust side of the water tank to vertically face the water tank and to rotate by head drop of water, an electric generator being coupled to a rotating shaft of the first water wheel; a heating boiler disposed to communicate with a lower portion of the first water wheel to generate vapor by heating inlet water; a vapor wheel disposed to rotate by high-pressure vapor ejected by communicating with a vapor exhausting end of the heating boiler, an electric generator being coupled to a rotating shaft of the vapor wheel; a condensing tank mounted at an upper side of the vapor wheel to have a first side communicating with the vapor wheel so as to condense vapor and to allow condensate water to flow toward an another side to exhaust it; and a second water wheel disposed to downwardly communicate with an exhaust side of the condensing tank, to rotate by head drop of the condensate, an electric generator being coupled to a rotating shaft of the second water wheel, and to downwardly communicate with the water tank; wherein a check valve is formed in the connection pipe to facilitate introduction of the vapor that comes up after the vapor wheel is rotated, into the condensing tank and to prevent the vapor introduced into the condensing tank from flowing backward, and wherein a portion of a second side of the condensing tank communicates with an upper portion of the second water wheel with the connection pipe and a control valve is coupled to the connection pipe to downwardly supply water at a predetermined supply rate.