To solve the problems of uncontrollable impact on patients and high maintenance costs after the failure of hospital diagnosis and treatment equipment, a preventive maintenance decision-making model based on uneven distribution of patient flow was proposed. Firstly, in view of the characteristics of the hospital treatment equipment degradation rate affected by the distribution of patient flow, the patient flow factor was used to reflect the changing law of its human flow, and the equipment degradation process model was constructed based on the equipment degradation evolution rule. Secondly, by incorporating the quantified cost of diagnosis and treatment equipment failure risk and the variable cost caused by delayed or early maintenance into the cost calculation system, an equipment maintenance strategy that constrains the failure risk value under the uneven distribution of patient flow was proposed. Finally, through the sparrow search algorithm (SSA) optimization to obtain the key initial variables, and numerical simulation analysis of the model, the results show that the maintenance strategy proposed in this paper can ensure the reliability of the diagnosis and treatment equipment while maintaining a low maintenance cost.