In the production scheduling process of systems with critical multiple components, system degradation is often influenced by various factors. Loads during production processing, external environmental impacts and the interdependence of component failures can all cause varying degrees of degradation in the system. Therefore, this article analyzes the degradation characteristics of key components and the system during production scheduling under the influence of multiple sources of degradation, and constructs corresponding degradation models. Based on this, a joint strategy for production scheduling and condition-based maintenance is proposed, with the processing sequence of scheduling jobs and preventive maintenance thresholds as decision variables, aiming to minimize the total weighted expected completion time, a joint decision model for production scheduling and condition-based maintenance of a homogeneous multi-component system considering the effects of multiple sources of degradation is constructed. Accordingly, derivations of component-level steady-state probabilities and system-level joint probabilities are conducted, and the numerical solution method is given. In numerical experiments, by comparing the optimization results of the joint decision model under the influence of different degradation factors, the necessity of considering multiple sources of degradation in joint decision-making is demonstrated. Through the sensitivity analysis of the parameters, the effectiveness of the proposed model is verified.