Demand-side information sharing was explored extensively in supply chain management literature. Research efforts have rarely been made into supply-side information sharing. In this paper, a simulation model with mixed-integer programming was built to simulate operating activities under supply information sharing in a three-level capacitated supply chain. The results indicate that supply information sharing significantly reduces total supply chain cost and enhances supply chain service level. In addition, the impacts of supply information sharing on the supply chain performance are heavily moderated by internal capacity tightness and external resources constraints. The findings provide important reference for supply chain managers to implement supply information sharing to improve decision-making process, reduce uncertainties, and increase visibility in supply chain operations.