In today’s society， the issue of frequent vehicle traffic accidents is still a serious practical problem. In order to ensure the trusted preservation and legal use of vehicle digital evidence， it is necessary to adopt advanced security technologies and strict access control mechanisms. Aiming at the preservation and sharing requirements of digital evidence on vehicle devices， an evidence preservation and access control scheme based on consortium blockchain was proposed. Firstly， based on consortium blockchain technology and InterPlanetary File System （IPFS）， on-chain and off-chain storage of the digital evidence was realized， while confidentiality of the evidence was guaranteed by symmetric key and integrity of the evidence was verified by hash value. Secondly， in the process of uploading， managing and downloading the digital evidence， an access control mechanism combining attributes and roles was introduced to realize fine-grained and dynamic access control management， thereby ensuring legal access and sharing of the evidence. Finally， comparison and performance analysis of the schemes were conducted. Experimental results show that the proposed scheme has confidentiality， integrity and non-repudiation with stability in the case of large number of concurrent requests.