Abstract: It is of great significance to acquire hydrogeological parameters efficiently,accurately and intelligently in the scientific management of groundwater resources and the safety construction of underground engineering.In this study,a novel intelligent inversion method of hydrogeological parameters is proposed.First,an improved arithmetic optimization algorithm (Chaotic Simplex Arithmetic Optimization Algorithm,CSAOA) is proposed.Chaos theory is used to initialize the particle positions in the search space.An adaptive adjustment strategy of hyperparameter based on stochastic optimization is introduced.Meanwhile,the simplex method is used to optimize the updating rule of particle positions,which further improves the local exploitation and exploration capability of the algorithm and reduces the probability of the algorithm falling into local optimum Then 8 benchmark functions are selected for numerical experiments.The results show that the CSAOA is superior to other comparison algorithms in early exploration speed and late local exploitation accuracy.In addition,the traditional manual type curve method is transformed into a global optimization problem based on optimization algorithm.The inversion model of hydrogeological parameters based on CSAOA is constructed,and an intelligent inversion method of hydrogeological parameters based on CSAOA is proposed.Finally,the method is validated in the parameter inversion examples of Theis and Hantush well flow models.Hydrogeological parameters are obtained quickly and accurately,and the intelligent identification of hydrogeological parameters is achieved.The results confirm the reliability and advancement of the method,and provide a new scheme for solving the inversion problem of hydrogeological parameters.