Urban storm intensity formula is one of the basic urban drainage design formulas. The accuracy and precision of the formula will be directly related to urban infrastructure security and economic rationality. The traditional solution method of the storm intensity formula is time-consuming and the accuracy is poor. The accuracy and precision of the current value iteration algorithm are good, but these methods require a continuous and differentiable objective function, if the function is Non-differentiable or without gradient information, these methods will fail. In response to these shortcomings, this paper uses the Genetic Algorithm to solve the storm intensity formula of the Tieling City to provide a reliable method.