The invention provides an evaluation method and device of a water pollution source, and relates to the technical field of environmental science. The method comprises the steps of obtaining the pollution equivalent number and the economic benefit data of a water pollution source; determining the water source pollution data of the water pollution source to a water source according to the pollution equivalent number. The pollution equivalence and the water source pollution data indicate the negative influence caused by the water pollution source, while the economic benefit data can explain the positive influence corresponding to the water pollution source, so that the evaluation data of the water pollution source is determined based on the pollution equivalent number, the economic benefit data and the water source pollution data, and the evaluation data can comprehensively and accurately evaluate the water pollution source.