The WM1800S outdoor small-scale water quality automatic monitoring system (hereinafter referred to as the micro station) belongs to an outdoor integrated station building, which has the characteristics of small footprint and easy installation, meeting the requirements of the main building and external supporting facilities of the water quality automatic monitoring system. It has an absolute advantage for on-site difficult to build station buildings and parks that require high-density water quality monitoring. Micro stations can simultaneously monitor nine conventional parameters online, including pH, dissolved oxygen, conductivity, turbidity, water temperature, permanganate index, ammonia nitrogen, total phosphorus, and total nitrogen. It can achieve automatic water sample collection and processing, real-time and hourly analysis of five parameters, water quality instrument analysis, automatic pipeline cleaning and algae removal, with minimal maintenance workload. The system covers an area of about 1 square meter and is easy to install and maintain. It is equipped with integrated air conditioning, constant temperature and humidity to ensure stable operation of the system. The outdoor cabinet has a protection level of IP54 or above, and is equipped with rain and lightning protection, power outage, water immersion, smoke detection, temperature and humidity alarm, etc. It can achieve all-weather unmanned operation.