The invention relates to an automatic water-feeding controller, which relates to the field of automatic control. The controller comprises a power supply circuit, a transformer, a rectifier filter voltage stabilizing circuit, an automatic control circuit and water sump probes. The power supply circuit comprises a three-phase power supply main switch (DK), a general protecting device (RD1), a main contactor (ZC) and a water pump motor (M). Any two phases of a three-phase power supply are connected with a main contactor coil (ZC) and a secondary protecting device (RD2) respectively. An input end of the transformer (B) is connected with any two phases of the three-phase power supply through power supply input terminals (3, 4), and an output end of the transformer (B) is connected with the rectifier filter voltage stabilizing circuit. The rectifier filter voltage stabilizing circuit consists of rectifier diodes (D1, D2, D3, D4), capacitors (C1, C2), and a three-port manostat (IC) which are in series-in parallel connections. The automatic control circuit consists of relays (J1, J2), triodes (Q1, Q3, Q4, Q5), a controlled silicon (Q2) and resistors (R1, R2, R3, R4, R5, R6) in series-parallel connections. The water sump probes (A, B, C) are connected with the automatic control circuit. The automatic water-feeding controller has the advantages of simple structure, safety and practicability without mechanical transmission control, and can save water and electricity resources.