Abstract: Optimization model of zirconium alloy tube ultrasonic testing parameter is established in this paper and the model employs a three layer RBF network. The input layer consists of rotation speed, feed speed and repetition frequency, whereas the output layer is of the standard deviation of the repeat test for artificial defect. The constructed network is of 2-8-1 type and the results of RBF module show that the mean square error is 0.004. The model is optimized by ultrasonic testing parameter, and it is determined that the optimal ultrasonic testing parameters for 9 mm×0.6 mm nuclear Zr-4 tube are 7 m·min-1 as the feed speed, 5 100 rpm as the rotation speed, 15 kHz as the repetition frequency. The result shows that the parameter optimization model is the new way to optimize the ultrasonic testing parameter.