The application of blockchain technology in business is more and more widespread. Business data mostly come from different data sources, the information representation is inconsistent, the information ambiguity between blocks in the same blockchain is too large, resulting in information consistency, credibility and value is difficult to evaluate, and other problems, this paper proposes a multi-source heterogeneous blockchain data quality assessment method for business activities. Firstly, the entity information representation method based on CEKGRL model is proposed, and the triplet structure of related entities is introduced into the blockchain, which is associated with the business activity category. The similarity is calculated through the context information to realize the consistency evaluation of blockchain information. Secondly, a credibility representation method based on information source, information comment and information content is proposed, and the credibility assessment of business activity information is obtained by fusing the representation results. Finally, on the basis of information credibility representation, the value evaluation method is introduced to evaluate the total value of business information in the blockchain, and the blockchain quality evaluation model is constructed. Experimental results show that the proposed method is superior to the existing methods in evaluating inter-block consistency, intra-block information credibility and value.