To make the best of the alkaloids, the main insecticidal components in Tripterygium wilfordii Hook. The extraction technology of the total alkaloid from root bark of T. wilfordii with acid ethanol was studied by method of orthogonal design. Combination artificial neural network with traditional orthogonal experiment, a new method for analyzing, processing and optimizing the test data was applied. By using this new method, the optimum extraction condition was obtained as follows: root bark powder 30 mesh, pH value 2.5, ethanol concentration 65%, solid-liquid ratio 1:10, duration of extraction 2h and extracting times 2. Applying this extracting technology, the costs of production was reduced, and the energy consuming was decreased, but the total alkaloid content was increased. The results show that this new method is reasonable and practicable.