The present study constructs a remanufacturing supply chain framework that encompasses both manufacturer and retailer. We conduct an in-depth investigation into the influence exerted by blockchain platforms in the supply chain, in response to carbon reduction challenges initiated by manufacturers. By introducing parameters such as the proportion of joint emission reduction investment costs and blockchain unit verification fees, we perform a comprehensive analysis of the effects produced by consumer sensitivity and blockchain platforms on sales prices, recycling prices, carbon emission reduction, market demand, amount of recycled, and profits under different emission reduction modes. Research has revealed that irrespective of whether the manufacturer adopts blockchain platforms, wholesale prices, retail prices, carbon emission reduction, market demand, manufacturer's profit in the joint emission reduction model are always higher than those in individual emission reduction model, while recycling prices and amount of recycled remain unchanged. With retailer's share of the carbon reduction investment cost kept within an appropriate range, both profits of retailer and supply chain increase under joint emission reduction model. When a manufacturer introduces blockchain technology platforms, unit verification fees only affect wholesale prices and have no impact on retail prices, recycling prices, carbon emission reduction, and profits.