In this paper, fuzzy control strategy is used to improve the stability of sub-mini underwater robots. The sub-mini underwater robots' fuzzy control method in the horizontal plane is mainly discussed here. Based on the language description of the model and according to the closed-loop system's dynamic model, the fuzzy controller language is educed with the inversion of the language model. The closed-loop system's stability can be ensured with this method, and its application on sub-mini underwater robots has not been reported yet. Results from simulation and experiments indicate that this control method has better stability and anti-jamming performance than variable structure PID control method.