PurposeThe purpose of this paper is to investigate the optimal operational strategies in a green platform supply chain and provide suggestions on the selection of sales and financing modes for the capital-constrained manufacturer.Design/methodology/approachThis study combines different sales channels with financing modes and investigates three sales-financing modes, i.e. traditional sales-prepayment financing (TSPF), traditional sales-bank financing (TSBF) and online sales e-retailer financing (OSEF). By establishing and comparing Stackelberg game models of these sales-financing modes from the perspectives of economy, environment and social welfare, the optimal strategies of emission reduction, financing, pricing and service improvement are obtained.FindingsThe results suggest that as the commission rate increases to a certain level, a threshold of the cost coefficient of emission reduction can be found such that the manufacturer should choose OSEF below this threshold and TSBF above this threshold. OSEF is Pareto optimal when this cost coefficient is low, and this mode can lead to the highest social welfare when the platform loan interest rate is relatively low. The Pareto areas in TSBF and OSEF enlarge as the default coefficient decreases.Practical implicationsThese results can provide operational insights on how to select sales channels and financing modes when manufacturer faces financial constraints in emission reduction.Originality/valueThis paper combines different sales and financing modes to study their comprehensive influence on the decision-makings of chain members and the resulting performance of economy, environment and social welfare.