In order to promote the sustainable development of the agricultural economy and ensure the authenticity of agricultural data and the safety of agricultural products, an agricultural trusted traceability model based on blockchain is proposed. The model utilizes blockchain to ensure data traceability and immutability while employing Elliptic Curve Digital Signature Algorithm (ECDSA) to prevent data tampering before being uploaded to the blockchain and to establish a responsibility traceability system. Additionally, in response to the significant storage capacity issues of blockchain, a storage optimization mechanism is designed based on the characteristics of agricultural data, aiming to reduce the storage pressure on nodes while ensuring data availability. Experimental results demonstrate that the model can achieve ECDSA within normal time costs and also show certain advantages in terms of storage consumption.