Crowdsourcing is a distributed approach to problem solving that reduces costs and efficiently utilizes resources. The introduction of blockchain technology solves the problem of over-centralization in traditional crowdsourcing platforms, but its transparency brings the risk of privacy leakage. The traditional anonymous authentication can hide the user""s identity, but there is the problem of anonymity abuse, and it also increases the difficulty of selecting workers. In this paper, we propose a decentralized accountable attribute-based authentication scheme and combine it with blockchain to design a novel crowdsourcing scheme. The scheme utilizes decentralized attribute-based encryption with non-interactive zero-knowledge proof to achieve linkability and traceability while protecting the privacy of users"" identities, and the requester can devise access policies to select workers. In addition, the scheme improves the security of the system by implementing attribute authorization authority and tracking groups through the threshold secret sharing technique. In this paper, we demonstrate through experimental simulation and analysis that the scheme meets the requirements of practical applications in terms of time and storage overhead.