Objective: In order to meet the refined requirements of temperature during the drying process of Penaeus vannamei freezing point and low temperature heat pump. Methods: A heat pump drying control system based on Siemens S7-300 PLC was designed. The system adopted a fuzzy control strategy. And a fuzzy controller with “two-dimensional input and one-dimensional output” was designed using the fuzzy logic toolbox of Matlab. According to the drying process of prawns, a data collection program and an execution program were designed to control the temperature of the drying oven. And the drying process was monitored and managed through the human-machine interface to realize automatic temperature control. Results: The temperature difference of freezing point temperature drying oven under fuzzy control was within 0.8 ℃, and that of low temperature drying oven was within 1.1 ℃. Compared with PID control, the temperature fluctuation range was reduced by 46.7% and 57.7% respectively. The dry test results of Penaeus vannamei showed that the freezing point and low temperature heat pump drying could effectively remove the moisture in the prawn, and better retain its color, whcih has certain advantages in shrinkage and rehydration. Conclusion: The control system operated stably and could quickly adjust the temperature of the drying oven. The control precision of the control system was high. And the control effect of this system was good.