Against the backdrop of the increasing demand for pet keeping and the rapid advancement of intelligent technology, the “Pet Companion” integrated pet health monitoring device has emerged. It is crucial for modern pet owners to raise their pets scientifically. In this article, the “Pet Companion” system, by leveraging multi-modal sensor fusion, cloud data storage, and mobile terminal applications, has established a comprehensive intelligent pet health management system. The system consists of hardware terminals, cloud platforms, and mobile apps. The hardware terminals are equipped with high-performance ARM control chips and integrate Beidou positioning chips, temperature and humidity monitoring modules, motion posture sensors, and smoke monitoring sensors, enabling 24-h continuous tracking of the pet’s movement status and related conditions. The cloud platform analyzes the collected data in real time, builds personalized health records, and promptly detects potential health risks through an abnormal warning mechanism. The mobile app provides pet owners with visual health data dashboards, abnormal alarm push notifications, and other functions, allowing for remote viewing of the pet’s status and environmental temperature and humidity. The “Pet Companion” reduces the risk of pet diseases through precise health monitoring and intelligent warning capabilities, providing a guarantee for the healthy growth of pets.