In recent years, with the acceleration of the domestic financial industry towards the Internet, electronic payment channels have become increasingly rich, and there are great differences in message format, communication protocol and business logic between channels. To reduce payment costs, enhance user experience, and simplify channel management, online payment platforms need to integrate the commonalities and characteristics between channels. However, many small banks still use traditional single node payment systems, which can no longer meet the needs of high concurrency scenarios in Internet finance. It is urgent to develop a new payment system with high concurrency processing capability and stability and reliability. This article is based on a distributed microservice architecture and designs and implements a daytime transaction module in an online payment platform. The system is developed using Java programming language and SpringBoot framework, combined with distributed features to enhance the system's concurrent processing capability and stability. Its technology stack includes MySQL as database support, Linux system as runtime environment, RabbitMQ providing message queue service, Dubbo implementing remote calling framework, Spring scheduled tasks responsible for scheduling tasks, and Maven for project management. The platform's functions include asynchronous notifications, channel routing, timeout queries, signature verification, and error code handling. It supports core business scenarios such as delegated collection and account recharge, providing practical reference for the design of high concurrency payment systems.