Abstract: To promote the application of new natural coagulants, in the process of tofu processing, lemon juice was used as a new type of natural acid coagulant, and the response surface method was used to optimize the production process. With texture characteristics and sensory scores as evaluation indexes, single-factor tests were conducted on the ratio of material to water, the amount of lemon juice added, the temperature of coagulant added and solidification time. On this basis, Box-Behnken response surface was designed to obtain the optimal processing conditions. The results showed that under the conditions of material/water ratio 1∶10, lemon juice volume 50%, coagulant added temperature 74 ℃ and solidification time 22 min, the tofu was bright in color, with rich bean flavor, delicate taste and smooth section. Internal voids are uniform. The results provide a theoretical basis for the development of new natural organic acid coagulants application in tofu processing.