A reliability-based topology optimization design method for a part structure considering bounded hybrid uncertainties, includes the following steps: considering the uncertainties in the manufacture and service of the part structure, describing an external load with insufficient samples and a material property with sufficient samples as an interval variable and a bounded probabilistic variable respectively; discretizing a design domain of the part structure, setting the physical and geometric constraints, and establishing a reliability-based topology optimization design model; solving by a moving asymptote algorithm: decoupling the probabilistic and interval uncertainties, and determining the worst working condition by using gradients of constraint performance functions; defining a performance fluctuation under the worst working condition and calculating reliability of constraint performance; and finally, calculating the gradients of objective and constraint functions with respect to the design variables for iteration.