Electroplating sludges are produced in wastewater treatment in metal processing, electronic component manufacturing and other industries with hazardous waste containing heavy metals. Many electroplating sludges about 10 million tons every year, have been produced in China. It contains various valuable metal elements such as Zn, Cu, Fe, Ni, Cr, its resource utilization potential is huge. The improper disposal of a large amount of sludges will also endanger human health and pollute the environment. The traditional chemical analysis testing process is complex, but energy-dispersive X-ray fluorescence (EDXRF) spectroscopy analysis is fast, simple, cost-effective, and can achieve in-situ detection. However, the high moisture content and unstable component content of electroplating sludge samples affect the accuracy of test results. It is a difficult to ensure the resource conversion efficiency of key elements and difficult to control environmental pollution. Therefore, it is necessary to analyze the mechanism of water influence in EDXRF detection and explore moisture correction methods to improve the accuracy of test results. The mechanism of the influence of moisture on the spectral background, scattering peak, and target element characteristic peak during the EDXRF testing process of electroplating sludge was studied. By the ratio of target element characteristic peak to Rayleigh scattering peak intensity, and the sample moisture content ω0(wt%) and target element content Ci%, a moisture correction model was established. The experimental correction factors in the moisture correction equation for Ca, Cr, Fe, Ni, Cu, Zn target elements were explored. The results show that the moisture correction model has high accuracy in correcting the five heavy metals Cr, Fe, Ni, Cu, and Zn, and the correlation coefficient R2 between the corrected value and the reference value is high, R2 are higher than 0.95, and RMSE are lesser than 0.05, indicating a low accuracy in correcting Ca elements R2 is 0.93. RMSE is 1.046 require further optimization by adding relevant correction factors. The research is expected to be applied to the moisture correction method for the on-site measurement of electroplating sludge disposal in the recycling copper industry, which can improve the utilization efficiency of electroplating sludge resources and reduce the risk of environmental pollution.