The invention discloses a drinking water purification pipe network pressure-superposed vector secondary water supply system. The drinking water purification pipe network pressure-superposed vector secondary water supply system is mainly composed of a non-negative-pressure pipe network pressure-superposed flow stabilization compensation device A, a centrifugal pump A, a speed governing permanent magnet motor A, an ultrafiltration membrane purification treatment device, a non-negative-pressure pipe network pressure-superposed flow stabilization compensation device B, an ultraviolet light disinfection device, a centrifugal pump B, a speed governing permanent magnet motor B, a washing pump, a control cabinet and a PC monitoring cabinet. The ultrafiltration membrane purification treatment device is used for filtering out contaminants such as microorganisms, bacteria, rust and the like in water so as to purify the water quality; the control cabinet is used for power distribution and automation control; and the PC monitoring cabinet is further arranged in the manner of matching the control cabinet and is connected and communicated with the control cabinet so as to be used for achieving the functions such as man-machine intelligence, monitoring, displaying and storage. The drinking water purification pipe network pressure-superposed vector secondary water supply system has the beneficial effects that the water quality purification and guaranteeing functions are achieved; in addition, non-negative-pressure direct concatenation water supply is adopted, so that the advantages of saving energy, water, land and investment, being free of pollution and the like are achieved; and permanent magnet motor vector control is adopted, so that the energy-saving effect of secondary water supply is further improved.