Abstract: Considering that some agricultural products were prone to high price foam due to their investment value, which would bring risks to product pricing, an improved supremum unit root test to measure the duration and intensity of price foam was proposed, and the influencing factors of tea prices with the help of bp-topsis model was analyzed, so as to carry out intelligent pricing calculation. The results showed that the GSADF values of product 1 and product 2 were 14.10 and 13.42 respectively, which were both higher than the corresponding simulation critical value of 2.35. Therefore, it indicated that there was a certain degree of price foam in both products. Moreover, product 1 had a high investment value, and its price foam value was between 320 and 1 770 yuan, which was much higher than that of product 2 with direct consumption value. Therefore, product 1 was at a high risk level in terms of foam burst. Thus the effectiveness of the model in preventing the risk of foam burst was verified.

Key words: tea, price foam, BP-TOPSIS, supremum unit root test