The invention provides an integrated observation system for the rice water requirement. The system comprises a water level observation well, a seepage measuring cylinder, a data acquisition device, amulti-path selection switch, an analog-digital converter, an F/V converter, a microprocessor, a data transmission module, a power supply module and a human-computer interaction unit. The water level observation well and the seepage measuring cylinder are all built in the paddy field. The data acquisition device comprises a water level sensor, a rainfall sensor and a liquid flowmeter. The water level sensor, the rainfall sensor and the liquid flowmeter are used for respectively collecting the depth of a field water layer and the depth of the water layer of the seepage measuring cylinder, the rainfall and the field water irrigation and drainage amount. The microprocessor packages all digital signals and then sends the digital signals to the human-computer interaction unit through the data transmission module. The human-computer interaction unit receives the digital signals, completes data storage, calculates the rice water requirement and displays a result. The power supply module supplies power to all electricity utilization modules. According to the invention, the water layer depth of the paddy field, the water layer depth of the seepage measuring cylinder, the rainfall and the field irrigation amount are continuously and accurately acquired in real time, and then the rice water requirement is calculated. The manual calculation is not needed, and the accuracy of the rice irrigation test result is guaranteed.