Nozzle flow model is indispensable in variable-rate spraying control based on pulse width modulation (PWM) technology, especially when nozzles are controlled independently. A variable-rate test platform which could control spraying pressure precisely and was easy to set PWM parameters was designed. The central composite orthogonal regression tests were completed by using the test platform, and the flow models of TEEJET AITXA nozzles of type 8002, 8003 and 8004 were obtained. The results of equation hypothesis test and test for lack of fit of flow models showed that the three flow models were agreeable. The maximum relative error of the TEEJET AITXA nozzle model of type 8002 was 7.05%, while the minimum relative error was 0.14%. For the type 8003, the maximum and minimum relative errors were 7.27% and 0.31%. And for the type 8004, the maximum and minimum relative errors were 7.94% and 0.71%. Nozzle flow model validation trials showed that the relative errors between model flow and actual flow were small. 