An automatic water level control system for multiple water tanks is composed of a controller, a water pump, at least one water tank, electrodes located in each water tank and electromagnetic valves located on the pipeline from the water pump to each water tank. Each electrode has three endpoints, which are located at the bottom, middle and upper parts of the water tank respectively. It is characterized in that the controller consists of a manual operation part, a water pump action control part and a plurality of other identical parts. And each of these same components consists of a sampling component, a logic processing component, a display component, a detection component and a pushing action component. (1) The mAnual operation part consists of negative power supply and button switch an; (2) The pump action control part consists of NOR gate Y5, NAND gate Y↓6] and diode D 1. D flip-flop LG [5] is in the counting state, which consists of tri-state low-pass gates S↓5] and S↓6], drivers QD5 and QD6, and water pump action relays J↓5] and J↓6]. (3) The sampling part consists of operational amplifier YF [I-]. Tri-state low gate s [I- 1], D trigger LGi and NAND gate Y [I- 1], (5) the display part consists of indicator driver DK I and high and low water level indicators L [I] and H [I], and (6) the driving action part consists of driver QD I and solenoid valve action relay J. (8) The output of the driving action part YF [I- 1] is connected to the L terminals of DK [I] and LG [I] and other inputs of Y [I- 1] through S [I- 1]. Y5] outputs one path to control the states of S5] and S6, one path enters the CP end of LG 5 through D 1 and C5], and the other path connected to an is connected to the input end of H-I- 1 The D and * terminals of LG 5 are connected to QD5 and QD6 through S5 and S6 respectively, thus being connected to J5 and J6 respectively.