Abstract: In traditional questionnaire systems, users are usually required to be authenticated before they can fill in the questionnaire, which may cause the disclosure of private information. At the same time, the traditional questionnaire system may have a problem that users fill in repeatedly. Aimed at the traditional system defects, a new system based on non-interactive zero-knowledge proof, message digest algorithm and blockchain is proposed. This system protected user's privacy data while ensuring that a user could only submit it once. The system implemented the questionnaire survey process with smart contracts to ensure openness, transparency and credibility. The system was actually deployed on Ethereum and the consumed gas was acceptable. The results show that the problems in the traditional questionnaire system can be solved.