A permanent-magnetic variable-frequency constant-pressure self-priming pump, comprising a permanent-magnetic brushless electric motor (1), a water pump (2) and an intelligent control system, wherein an inner end of a lower side portion of a pump head (21) of the water pump (2) is connected to an output end of the permanent-magnetic brushless electric motor (1), and an outer end thereof is connected to a pressure tank (22); the pressure tank (22) is in communication with a water outlet cavity; the intelligent control system comprises a line cover box (3) arranged on the permanent-magnetic brushless electric motor (1), an intelligent drive plate (33) arranged in the line cover box (3), and a liquid crystal touch-control screen (32) arranged at the top of the line cover box (3); the intelligent drive plate (33) is electrically connected to the permanent-magnetic brushless electric motor (1) and the liquid crystal touch-control screen (32) by means of a power supply line; the pump head (21) is also provided with a water pressure sensor (34) extending to the interior of the pump head (21); and the water pressure sensor (34) is electrically connected to the intelligent drive plate (33) by means of the power supply line so as to feed back water pressure.