Current e-commerce payment systems need a payment gateway for making payments. This attracts payment gateway charges; participation in e-commerce will become costly; and it also raises issues with online payments and data security. Current outsourcing services use payment gateways that leave payment details vulnerable to third parties and outsiders, which may cause data insecurity. The development of payment gateway-free outsourcing services has led more and more individuals and businesses to take advantage of the cutting-edge services of e-commerce service providers. Therefore, we developed a decentralized outsourcing service with a safe and fair payment system based on blockchain technology without any need for a third-party payment gateway. The design of the system is vigorous and also suitable for blockchains. Algorithms and encryption processes used in blockchain transactions make the payment process safe and secure. These technologies are used to build a decentralized payment system for outsourcing service platforms. Through this research, e-commerce users and sellers can safely and conveniently make payments through the blockchain system.