In supply chain management, a common scenario lies in proving an entity’s ability, e.g., a supplier needs to prove its supplying ability by revealing its commodity transactions often have quantity constraints (e.g., minimum order quantity and maximum supply capacity). However, traditional verification mechanisms require the trading participants to disclose their core business secrets, which poses significant risks of commercial privacy leakage. To meet the verification requirements of business constraints while strictly protecting the sensitive data of all participants, this study proposes a verifiable privacy protection protocol based on non-interactive zero-knowledge range proof and blockchain technology. The core innovation of this framework lies in enabling suppliers to generate and submit cryptographic proofs to purchasers (namely as a verifier) without revealing their exact production capacity, thereby efficiently and reliably proving their ability to meet specific transaction quantity requirements. In addition, the process is designed atop blockchain, which, acting as an infrastructure of supply chain, plays the role of recording immutable transactions of proofs and coordinating participants. Security analysis is performed and experiment is conducted to showcase the protocol’s efficacy and efficiency.