In order to achieve precise monitoring of key indicators of fish pond water quality and optimize water quality management, a cloud based monitoring technology for fish pond water quality based on multi-source data collection of the Internet of Things is proposed. Using the AS950 water quality automatic sampler as the data collection device for monitoring technology in this article, the reasonable layout of the AS950 water quality automatic sampler can achieve multi-source collection of fish pond water quality. Using STRIDE of the Internet of Things to build a lightweight cloud transmission protocol that is connected and provides reliable transmission, the cloud transmits multi-source fish pond water quality data collected by the AS950 water quality automatic sampler. At the same time, on the basis of improving the empirical mode decomposition method, analyze the cloud transmission of multi-source fish pond water quality data, and obtain accurate monitoring results for various indicators of fish pond water quality. The experimental results show that the cloud based monitoring technology for fish pond water quality based on multi-source data collection of the Internet of Things designed in this paper demonstrates excellent performance in comparison, with extremely high fit to the actual situation and minimal deviation. Specifically, the pH monitoring error is less than 0.01, the total nitrogen monitoring deviation is controlled within 0.05mg/L, the total phosphorus monitoring deviation is only 0.03mg/L, and the permanganate index monitoring results are basically consistent with the actual values. These data fully validate the high precision and reliability of this technology in water quality monitoring.