<p>This paper uses sudden events as a critical point and develops a two-stage dynamic pricing model, before the event, customers maintain a stable valuation of the products, but following the event, their valuations undergo an abrupt and uncertain change. Due to the rapid development of information technology, retailers can effectively process and analyze large amounts of customer data. However, retailers are often unwilling to provide demand information to suppliers due to potential profit losses. Given the uncertainty in consumer valuation fluctuation, this study further investigates the retailer’s information acquisition and sharing strategies. We find that when the retailer acquires information but does not share it, the information leakage effect benefits the supplier but hurts the retailer and the supply chain, the leakage effect will be higher if the customer valuation in the second stage is higher. The supplier and the retailer with negative valuation information moderately raise the price in the first stage to discourage customers from stockpiling in advance. The information-sharing mechanism between the retailer and the supplier becomes easier to implement if the valuation discount in the second period is lower, the initial customer valuation fluctuation information is less precise, and the retailer’s information is more accurate.</p>